I was migrated from sse to ovo,I left sse in credit and final bill all paid.my first opening statement with ovo they had added £629 on my account for no reason,I was told after ringing them it was a billing data error from sse, total rubbish.Then in the next month I was told my balance in debit was £2,700 then the next month it is now £2,200.they are changing me over £2,100 for one month of gas usage in September this year,when my average consumption is around £40.It has been investigated on two case investigation's with them and never a final outcome and know information sent to me.As other people have said they need to be investigated not only with ofgem as they already have, and they still continue with same practice.I have been laughed at by customer service for making a complaint,had phone put down on me when I asked a question they can't answer, complaints not recorded or passed on.