African bank does respect agreements with their clients

African bank called me earlier twice during the month of december to set up a payment arrangement for my loan. Both times we agreed on a recorded line that i will pay an amount of R250 due to go off on 22 December and they sent me an sms confirmation of this agreement on 17 December. Few days later they deduct over R1500 despite our agreement. Not only that but on the 22nd of December they still deducted the R250 in addition to the R1500+ they had already taken. This is complete nonsense. I want my money back and im definitely closing this account.