3 months now and still no response

My name is ZamaNdosi Mrwebi and I took out a laptop contract with a modem on a 1GB price plan at R399 per month at the end of September 2015. I went to fetch the devices and I was told they were out of stock of modems, so they gave me a wifi router. I was told they are offline every time I went into the shop to get my device connected, I finally was able to connect at the end of October 2015 but when I connected and tried going on the internet, it showed insufficient data. I then went back into the shop to check what the problem was, I then found out I was on the wrong price plan, a 500MB price plan instead of the 1GB. A gentleman called Dewaldt said he would take care of it. He explained to that they must first cancel the contract then do a new application for the my contract to be on the correct price plan. He told he had sent through the documentation to the relevant department and it would take 21 days and I would be connected by that relevant department. 21 days passed, I had not received any phone call. So I went back to the shop to find out what was happening with my case. All they could tell me was it is still in process. Another 21 days passed, still no response till today