Broadband customers are being hit with cancellation fees of up to £625, the Citizens Advice Bureau has warned.
The consumer charity said consumers who challenge the fees soon found themselves in the hands of debt collectors.
Other customers became locked into a broadband service which did not meet their needs or were hit by excessive fees when they tried to switch providers.
One woman was hit by a cancellation fee, even though it was not in the terms and conditions of her contract, when she tried to switch provider after her broadband speed became so bad that she was paying repeatedly to use an internet cafe.
Citizens Advice chief executive Gillian Guy called on internet service providers (ISP) to "not shackle customers" and ditch cancellation fees altogether.
UK Broadband has launched a new service that "does not require a landline" in order to operate.
The internet service provider has unveiled a new service, called Relish, which will supply London with "fibre-fast speeds" of internet access for customers - without a phone line.
The Relish service includes a traditional router, which only needs to be plugged into a power source to access the internet, eliminating the need for a landline.
A new report has named the 10 slowest and 10 fastest streets in the UK for broadband speeds - is yours on the list?Read the full story ›
BT is "not impacting on rural communities" despite winning all of the rural broadband contracts from the Government, the head of an influential committee has said.
Labour's Margaret Hodge warned other competitors "might be squeezed out" of the rural broadband market by BT's dominance.
Whilst BT claims it is making further concessions, this is not impacting on rural communities.
Local authorities are still contractually prevented from sharing information to see if they are securing best terms for the public money they spend.
Communities can still not access the detailed data they need to understand whether they will be covered by BT's scheme in their area.
Other broadband providers might be squeezed out of the rural market by BT's actions.
BT has an "effective monopoly" over rural broadband after the Government awarded all of the 44 contracts from the £1.2bn scheme to the telecommunications giant, a group of influential MPs has said.
In another another scathing report of the rural broadband scheme the Public Accounts Committee (PAC) said the way it had been set up "failed to deliver meaningful competition".
This meant BT had been put in a strong position by the Department of Culture, Media and Sport (DCMS) making it more difficult for customers to insist on value for money, according to PAC.
Margaret Hodge, who chairs PAC, said: "Since our hearing in July last year, when 26 of the 44 contracts to deliver this were with BT, all remaining contracts have now also gone to BT.
"Despite our warnings last September, the Department for Culture, Media and Sport has allowed poor cost transparency and the lack of detailed broadband rollout plans to create conditions whereby alternative suppliers may be crowded out."
Ofcom have defended internet providers after reviewing the ability of companies like BT and Sky to stick to a voluntary code of practice.
A spokeswoman for the industry watchdog admitted there were some areas that needed to be "strengthened further" but said "overall the code is working effectively".
Ensuring consumers receive a high quality of service from their broadband provider and are fairly treated are high priorities for Ofcom.
That is why, in 2008, we introduced a broadband speeds voluntary code of practice to ensure consumers are protected...
Mystery shopping conducted last year by Ofcom revealed that, overall, the code is working effectively.
We have, however, already identified areas where it might be strengthened further and have discussed improvements with providers to better serve consumers.
We expect to publish a revised code of practice in the coming months.
Over a third of broadband customers said they have an internet connection which frequently drops out, a survey from Which? revealed.
According to the consumer group:
- One in seven have not been able to connect to the internet at all on more than one occasion.
- Of the 45% experiencing slow speeds, 58% said this was a frequent or constant problem.
- Poor customer service was also exposed by the survey - Around one quarter (27%) have waited more than two days for after reporting a loss for anything to be done.
- Some 11% waited a week or more.
- The watchdog found 31% who contacted their provider with a problem did not get a resolution at all.
Broadband companies have been accused of charging some customers for speeds they are not able to get, with nearly half of people suffering from a slow connection, according to a consumer group.
Which? found 63% of the 2,012 broadband users quizzed experienced problems with their internet and 45% suffer through slow download speeds.
They are calling on providers to give their customers "the speed and service they pay for".
Which? executive director Richard Lloyd said: "The internet is an essential part of modern life, yet millions of us are getting frustratingly slow speeds and having to wait days to get reconnected when things go wrong.
"It's less superfast broadband, more super slow service from companies who are expecting people to pay for speeds they may never get."
Nearly two-thirds (62%) of those questioned said they have no idea how much internet data they actually use as part of entertainment bundles they pay for, while almost a third of respondents (29%) do not know what capacity they are paying for.
Although an increasing number of consumers are putting their hands in their pockets to pay for additional online streaming services, there is still a considerable amount of cash wasted on paid-for TV channels which go unwatched.
People should regularly assess their viewing habits to ensure they are getting value for money from their TV service.
The cost of TV "wastage" - the amount spent on paid-for channels that are going unwatched - has decreased since last year.
With the cost of TV entertainment within a bundle averaging at £22 per month in 2014, households are spending £195.35 annually on unwatched TV channels.
The report was issued by the Post Office and Freeview.
The amount households spend on entertainment bundles has increased to record levels, a national review of internet users' spending habits has shown.
Vision and Value 2014 - an examination of television, broadband and home phone usage among consumers who choose to bundle the services - found that monthly spending on bundles has increased since 2013, costing each household an average of £50 per month.
This equates to an overall national spend of £3.3 billion - the highest it has ever been.
The report also found that almost one in five UK bundle users is spending an additional £10 per month for online TV subscriptions.