African Bank - retrenchment cover

My husband was retrenched in September 2017 and at the time had an up to date African Bank account, 2 weeks after his retrenchment he submitted his retrenchment documents to African Bank at one of their branches. He was informed that the retrenchment insurance would cover his outstanding balance and that he needed to submit an affidavit every 3 months to confirm his unemployment. This was done diligently and he was informed that at end of may 2018 the outstanding balances on his account would be cleared. When applying to a personnel agency in March they did the normal checks including a credit check which is when he learned that his account has been incurring interest and listed as not paid, he contacted African Bank HO and was infirmed the insurance was approved. When he went to a local branch a few days later to follow up on the status of the insurance he was then informed the account is flagged for legal!!!! he has been struggling with African Bank for over a month now and was requested on the 19/04/18 to resubmit all his documents which he did ONLY to be informed via sms they cannot process the insurance claim as his documents were submitted too late. So my question to African Bank is who is to be held liable for African Bank staff not doing their jobs properly when all the necessary documents were submitted way ahead of the requested timelines, is my husband to accept that he is now liable for this balance even though he had paid his retrenchment insurance and account up until the month of his retrenchment??? Over and above this this mark on his credit report is affecting the jobs he may apply for to obtain employment. African Bank has not been helpful at all in resolving this and is sticking to their excurse of documents were submitted late PLEASE HELP