Mtn
Mtn client service not helpfull

I took out a data contract and when my fist bill came I figured out I was on the wrong package so I went to the store and after about two months they got me on the right package then I got a very high bill that they overcharged me for there error I have since trying to get that money refunded the lady at the shop showed me a email of the complaint and the response was it will be refunded but five months later still no refund and the shop says they don't know what else to do. I have tried the help line bit no success as well