limit removed and left with R1000 data bill!!!!!!

this is a long story, so I hope the correct person get this! I called the Upgrades & Retentions department at the beginning of November 2015 to find out about my MTM 2GIG contract being renewed. My call was taken by Arnold who was saying there was a current special of R89 for the 2GIG contract and he would upgrade my contract, which I agreed to. He then went on about how I was due for an additional contract from my 072 ### ##90 and he could offer me a Samsung Neo etc... I did inform him I was not due for an upgrade on this number but he insisted. Finally he realised that I was not due an upgrade and recanted. I went into the Autopage branch in Westwood mall about 2 weeks later to get 2 tablets for my younger children for Christmas. I asked the manager to check if this contact was upgraded, she said nothing was done and offered to upgrade it. I said to leave it and I would contact the retentions department and enquire why this was not upgraded as agreed 2 weeks back. unfortunately with my busy time at work, I left it until now when I discovered that I now have a R1000 data bill!!!!! I need to know who took off the cap on my 2GIG limit!!! I understand if the upgrade was don