NO HELP!

I have been having endless problems for the past 4 months with my network connection. I have phoned the call center and every other department where I was referred to, and still my issue has not been resolved. <br> I done a sim swop, I have logged numerous complaints with MTN coverage for the fact that my network switches on and off wherever I am. It shows a circle with a line through and sometimes just stays there for hours even when I restart my tablet. This is really ludacris, I had a Vodacom sim card in my tablet for two weeks and never had any issues, which tells me that MTN is the problem. I have even upgraded the software on my tablet twice! And still this stupid problem is not resolved. I am paying this contract every month, and I can't even use the data I get. I have to always be connected to WIFI to use my device which is unacceptable. Pleeeaaaaaaaaaaaase I am frustrated with this already, HELP ME.<br> <br> P.S If this matter is not resolved within the next two weeks, I want my contract cancelled! And I refuse to pay any extra cost.