They don’t debit when they should and wait for the debt to pile up so that they. An take money I don’t have

I took out a personal loan just before lockdown and made repayment agreements, Nedbank was to debit their money every month from me, for the pst 2 months they have been debited and reversing orders themselves,plus additional R617, which no one accounted for,I tried calling them to find out what’s is happening to no avail, their consultant called and I told them nothing has changed, they must debit now I must pay R3817.00 which I didn’t budget for, this is unprofessional when you call them there’s no one to answer their phones, when debiting so much money without actually consulting me what must I live with, head office may you call me back ASAP failure to do so I will contact the ombudsman