MTN's pathetic service

I decided to not upgrade my 15yr+ old contract because I retire in a year. I wanted to keep my nr and moved to pre-paid by calling their 135 call centre as instructed by the MTN Glen branch, on Nov 26th. Since then I can't access my data, even though I've got 4gig available. I find the lack of interest by ALL the staff shocking, from the Glen store, to the call Centre to the 14th Ave branch. Let me clear up something, my phone is new and worked perfectly before migration. The Glen did a sim swop, but second sim had the same problem....then they lost interest and told me that they do not know what I can do, except call 135 again....which I did..... on a daily basis....the best they could do was saying I must switch off my phone and on again and it will work in 24hours....and the next day I would try again. I tried 14th Ave because I thought that was the MTN HQ? No luck there either! I bought extra data hoping that would work, but I can see the data, just not connect to it. The problem must be on the MTN side, looks like the data is blocked, but I can't find anybody interested. PLEASE CAN SOMEBODY HELP? IT'S BEEN ALMOST 2 WEEKS!