i recently moved to a new address and a new gas and electric supplier. i had my old gas and electric which were both with british gas closed on the 10th and 11th june 2014 but final days of use were sunday 8th june 2014. i gave them the final readings and accounts were closed. However british gas have now informed me that they have made a error on the gas account. i checked it and yes they made a big error which is as follows they had billed me £0.00 for periods of 21st Feb 2014 to 23rd may 2014 bill showed a usage of £0.00 (Yes a big flat nothing) even thou there was a usage there system produced a bill showing no details at all except in the comparrison box for this year to last year it shows usage of 2171.40 kWh bill dated 28th may 2014 , no other details of unit rate , no readings , no calorific value , no standing order charges , no days usage , basically no details at all. Then my closing bill dated 11th june 2014 again shows a £0.00 usage in cost again , but shows readings , amount used , calorific rate but a cost per unit of £0.00 (Zero) and no standing charges but states days used 16 but again in comparrison box for this year to last year shows a usage of 443.14 kWh. Now my accounts were closed before they found out there error with there system. Not my error as i supplied them with meter readings that were accurate and i pay by direct/debit monthly so hardly ever check my bills just the meter reading section. Now this type of error was done on the gas account on the standard tarrif by there computer system and there fault not mine. As far as i understand it , it is there error and since my accounts were closed and final bills and balances issued they can not make me pay for there errors. Also i assume there must be 100's or 1000's of other customers on the same tarriff with the same errors so why should i be singled out and asked to pay for this error they made and others note. just because i moved house and gone to another supplier they seem to of picked up on the error and now want it all paid in one go. So some advise here please. if its there on fault and error do i need to pay. if others have the same error can they just single me out and make me pay because i have left them and moved and got a new supplier. If my account already had the final readings accepted and account closed can they legally make a change to bills dating back to 21st feb 2014 when its now june 2014 and accounts already closed and force me to pay for there error.