"Account not in good standing order", but FNB cannot tell me which one !!

After many years I suddenly did not receive ebucks for July with the reason given that one of my accounts is not in good standing order. My credit card is always paid long before the due date and my cheque account has never been in the red. I first contacted Ebucks via email (twice) with no response, then by phone, to find out which account is "not in good standing order". "Sorry, we cannot check". Then contacted Premier bankers - 4 emails - NO RESPONSE; via phone: same response: one account ..., but sorry I can not determine which one. A month later, and I'm again not going to get any e-bucks. WHY CAN NOBODY TELL ME WHICH ACCOUNT IT IS, so that I can rectify it???