Ofgem is also conducting mis-selling investigations into Scottish Power, Npower and E.ON.
In April 2012, EDF Energy agreed to pay a £4.5m fine to help vulnerable customers for breaching marketing licence conditions.
We speak to one of those who was actually doing the selling. He left the job because he found he had to 'take advantage of a human being.'
A guide to some of the options open to you as a consumer if you believe you have been mis-sold to by SSE or any other energy company.
Ofgem's £10.5m fine imposed on SSE is the biggest ever authorities have imposed on an energy supplier.