Double debit

Mfc debited my account for my car for the amount of R1720. Monday (23/10/2017) I received a sms from mfc stating that my account is in arrears and wil debit a amount from my account of R1620 and if there is any inquiry I must call them. I did call them and spoke toe Adrian du toit and explained to him they already debited my installment for my car and he assured me that it's a problem from their side and he wil monitor my account and prevent them from double debiting my account witch he dit not do and I paid a double installment for my car this month I'm very upset with them and I think highly unprofessional as Im working on a budget and don't think they have the right to bouble debit my account as they please and being skaily and do it under different naming and amounts. 1St installment was for R1720 under (magtape services) and second one of amount R1620 under (debit)