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."
More top news
HSBC has reported a 10% rise in profits for the first half of the year - boosted by bumper profits in Hong Kong.
Barnado's has received £3 million to tackle child sex abuse in Rotherham, nearly a year after the Jay Report was released.
Lord Sugar has told Katie Hopkins to "shut up" after the ex-Apprentice contestant criticised celebrities who paid tribute to Cilla Black.