Cellphone Mix not connected to network

My cellphone mix is in use since 2012. During the last week in March 2015 is disconnected from Telkom network. Since then, NEARLY THREE MONTHS NOW AND close to 20 VISITS AND 5 REPLACEMENTS of the sim card and several phone calls to the technical department from the shop and my home, still nothing has been done to connect the phone. I have also been to see the manager of the store and was promised by him that he will try to sort out the problem. After another 2 weeks still nothing!!!!! NO WHAT MORE CAN I DO TO GET HELP OR RESULT from TELKOM. I still have to pay my contract monthly installments otherwise THAT WILL BE ANOTHER PROBLEM TO TRY TO SORT OUT!!!!!