Do you know you can switch to direct debit?
If you have a smart meter and you're Pay as You Go top up in shops etc. go onto USwitch and pick any company to switch to, tell them your a direct debit customer with your current company and in 3 weeks the new company will take you on as a direct debit customer and they'll change the smart meter to direct debit..
I went to CAB about my bills and the man said to do this and now we're direct debit so we don't have to worry about how much we're using. It's cheaper than payg. It's still expensive obviously but you pay a lot less.
Hope this helps someone