Poor service

Terrible service from telkom Mobile upgraded and and changed my debit date with consultant at their Southgate branch l and I was told it was sorted. The first debit went off on the new date after that they would debit on the old date sometimes on the new one. Now they are charging me penalty fees which I was never informed of when they don't get the subscription with no notification they debit my account spoke to a consultant today who literally said it all my fault when I asked to change debit date she said it has been changed but they are still going to debit on the old date new date will only apply next month so again there won't be funds and I'll be charged a penalty fee