Wrong Payment taken off and NOT reimbursing me

I tried getting a contract with MTN. I had to complete the online form around 4 times before I even got a call. I was told that I could port my number from Vodacom to MTN and when I finally got my Sim Card delivered to me, I was informed by the MTN Store in Menlyn that my number cannot be transferred (the Grove store couldn't even help me). Then my contract was cancelled on the 17th of December 2019, however, MTN then deducted an amount of R252.06 on the 31st of December 2019 and has still not reimbursed me for this. I have called the online sales (Buymondo) twice to follow up and now it's almost a month later and I still have not received my reimbur*****t. Please pay me back my money!