Double debit

Im very disappointed with the service I received from African Bank after my agreement with them on the 21st this month I went to the branch in verulam to explain about my financial constrain that I'm facing since I'm having short time at work to reduce my installment from R2168 to R1000 per month for 3 months starting from 25th this month the consultant help me to call their call center to arrange that agreement for me everything went well I received the confirmation sms aprooved my R1000 debit order. The problem started when they debit on the 24th R2168 on my bank account and I called them to find out the agent that I spoke to promised me to reverse the money within 24 hours, boom again on wensday morning the 25th R1000 debit order notification what I don't understand how can they double debit me while I explain my situation I'm facing and what about the agreement we made last time. I'm not going to call them anymore since I'm using my airtym if they not settling this matter by reversing my money I will take this matter further to ombudsman its unfair.