BANK NOT KEEPING TO THE ARRANGMENTS MADE

Hi had an payment arrangement with African bank and always paid according to the arrangement of R550, African bank decided to deduct (Debit) R2200 way more then our agreement and resulting me not to paying rent this month. There a reason why arrangement been put into place. I called twice over the weekend to the contact center and been advised to call on Monday and talk to the collection department to have the money reversed. Monday already i needed to load R100 of airtime as the waiting period always long, I have spoken to several agent not being helpful and eventually one lady advised I need to send a email to request for a refund on *** which I did and 3 follow ups and no response. I HONESTLY NEED MY REFUND OR DO I SIT ON THE ROAD. I'm getting to scared seeing that it is getting to December and the way the bank can do as they please. DO WE CHANGE BANKS IN THIS TIME.