called to change bank details, changed yet still debit wrong account and now i have incurred costs because you didnt update your system.

called to change bank details, changed yet still debit wrong account and now i have incurred costs because you didnt update your system. i called on the 15th of july to customer care to update my banking details. confirmation it was done on same day. yet, 1 August, still debit the old account. come 1 september, you still debit the wrong account. when i called, (the accounts dept 1946) i was told they dont have the correct details and i should have told them. i said i called customer care. thats my obligation. not the collections deprtment. this info should have been updated on YOUR system. then i get told you would do another debit order. lo and behold, still the wrong account. and the debit order bounced as there was no money in the account. i want the charges reversed as well as payment for the late payments as this was not my fault. yet the incompetency of either the staff or the systems you have.