MiWay debit order

Very disappointed with MiWay, they deducted an additional R1000 on my installment and cannot give me a clear reason why, and now i need to send them my bank statements to get my own money back and I now need to go into the branch to get as they only roll on a 3 month basis, a transaction history will not suffice and on top of that it will take 3-7 working days to refund. I have planed my money accordingly and with this lockdown I was counting on every penny.I am no huge earner that can just accept R1000 to be taken and whenever the money is refunded it is refunded. This is totally unacceptable