They took my money now they don't want to pay me back

I would like to express my disappointment with the service I've received from these guys. I paid the settlement on the 4th of May and I sent them the proof of payment and they said they will allocate it and it will reflect into my account. They decided to debit R2003 from my account which is money I need to pay school fees for my child which in fact I no longer owe them anything at this point. I called them last week Monday and they said they will pay me back and it will reflect Wednesday 28th of May but I did not receive anything. I called them again and they said nothing was allocated and they will work on it, they apologized and said they will allocate it and my money will reflect on Friday. I called them again and they said it will reflect today but still. Right now my patience has run out and I will have to escalate this issue. I want my money back.