No assistance on double debit by FNB

I checked my FNB banking app this morning and I see FNB debited me twice for a loan repayment. I tried to query this on their secure chat on the app and was sent a number to call. When I called the number I was simply told to call back tomorrow there's nothing showing on their side. Meanwhile I have other debit orders that need to find money available in my account, I can't tell them "call tomorrow". What an inconvenience topped off with shoddy customer service. Really thinking of moving back to Standard Bank at this point