Could be worse....
Last year I moved out of the flat I was renting (it was elec only). I was there for 6 months which just so happened to also be winter months. When I first moved in and set my account up with E-on I told the guy on the phone all the details of the property so that he could put me on a price plan that would reflect my typical usage. He suggested £54/month. Once I moved out I phoned them up to give them an accurate meter reading and asked them to close the account. I was expecting a small credit or debit (most likely a small debit as it was winter) to be sent through to me. I got a bill saying I owed them in excess of £700......
So....1 bedroom flat with 2 people in it -
Paid £54/month x 6 months = £324 (as suggested by them...)
Get stung with £700+ final bill on top which they took out of my account without any warning under the same direct debit that was set up for the £54.