Credit limit incorrectly set

I had my sons cell phone upgraded. I filled in the necessary documentation at MTN Hemingways Mall in East London. They then emailed it to Charlene Weideman at MTN Greenacres in Port Elizabeth. My son lives in Port Elizabeth as he is a student there. He duly collected the new phone from Charlene. They were given strict instructions that the contract must under no circumstances change and that it must remain exactly the same TOP UP Package as before. <br> <br> My total bill per month at the moment should be R1671.00. At the end of June my Stop Order was R1912.84. I then went to MTN at Hemingways Mall in East London and they logged a query. The response to the query was that the upgrade was processed on 15/05 2015 but the credit limit was only set on 29/05 2015.<br> <br> Needless to say I am not happy with the outcome. Then to add to the problem at the end of July my bill and Stop Order was R2314.08.<br> <br> I therefore request that this matter is rectified and that my account credited with the amount that I have been overcharged on the two billing accounts as MTN Greenacres Port Elizabeth messed up.