Poor performance from Private banking

My son has a study loan that is linked on my name which he pays via his banking account. The bank never took the money out his account (via debitorder) and now for two weeks Ive been sent from pilar to post to have this sorted out... Im Private bank client and constantly have to request updates from my banker.. .. this is still not sorted out. I want to know where the problem lies. Personal loans dept advised my son's account is closed.... but his had his account with FNB for about 7 years now. Tried to sort this out via Secure chat but the is the most unhelpful platform in online banking