Sim card still not working

I had a contract with Nashua Mobile which was taken over by Autopage Cellular. In January 2015 the contract expired and they promised that they will covert it to prepaid.This was done but when I called the Call Centre to complain that the sim card is not working they said I had to go to Cell C for a sim swop but they referred me to Autopage again. I went on the 07/02 and did the sim swop and they promised that it will work that Monday or Tuesday but it was not working.I have been to the store numerous times and until today it's not working. This type of service is unacceptable as its been a month of promises and it's still not working. Please could we get some type of service to get the sim card to work. Number is ***