MTN Dishonest company and definitely no service

Hello Peter MTN is dishonest when it comes to refund a customer for money that was taken off *******ly and proven. I upgraded earlier before it was due and was informed in store that i have to pay R2000 in for the early upgrade for the hardware. I had a choice whether i want it to be charged on my next bill or pay upfront in store. I paid upfront in store and when i got my bill it again was charged on the bill. I contacted the call centre (what a disaster) and they informed me i must go instore and sort it out. I went and got a REF. NO. Got a message from MTN later that the complaint was sorted and the case closed. THAT'S IT. Went back to the store and got another REF. NO. Got a message from MTN again and said it was sorted and case closed. Up to date i have not received a refund whatsoever and they still owe me the R2000.