Debit my account for no reason?

My account was debited with R2000 on the 8th Dec for no reason? I have paid my monthly payment on the 6th Dec and recieve an sms yesterday that R2000 was debited out of my account? I called an they can tell me why? I have send the payment transaction documents and waiting on feedback. Please transfer my money back into my account please?

I have also been trying for the passed 2 weeks to app**** for an upgrade but no luck my deal was approved and the consultant said i will get my new phone with in 5 to 7 work days ( that was a week again) and the i got ant email my order was declined, then they send me an sms that i will get and call from 021 688 ***X to finalize my order ? every time i check i get miss call from that number but my phone didn't even ring? I called telkom again and hold for more the 30 min at a time and when i finally got someone on line the ladies said needed to call upgrades? Can someone please assist me please?