Iresa - Accounts in credit

Hello,


I have been dealing with Iresa via email as my electricity and gas accounts are in £74.56 & £48.60 credit respectively. I thought seeing as my direct debit is currently £69 i would be able to simply withdraw the credit funds to take my accounts back down to zero.

I have just received this from Iresa:


"If your direct debit payment is pending at the moment of the excess credit refund, the system registers it as it non-existent and in turn considers the leftover credit on your account as the only possible way to cover your direct debit payment amount.


When we issued your refund it was the maximum allowed amount by our system"


Can anybody help as to why i am not permitted to withdraw all the credit funds when in theory this is my money?

Thank you,