Upgrade deal

In July this year I app**** to upgrade my contract. I went to the MTN store in the mall@carnival to request my upgrade. I filled in all the forms and gave all required documents, to upgrade to the Mychoice 100 deal which was adverted at R369pm. I was told that there was no stock of the phone (Sony Z3) and I would have to wait to get the phone. <br> <br> After a week or so I contacted the store to see if they got stock, but no stock has arrived. I then contacted the upgrade center and was told that there is stock and that they could do the upgrade for me, all I had to do was cancel my order with the store and apply through them. <br> <br> I did just that, but now I see that I am getting billed R429pm instead of R369pm? I have queried this twice via the online platform, but have received no response as yet. Now I have been soft locked because I have not paid the full amount. I now saw that there is the same deal that is R299pm with 200Mb more data??***<br> <br> I would like my account rectified to reflect that my contract should be R369pm and be migrated to the R299pm deal and be unlocked.