Stuck in contract

Been going to MTN every Month for the last 3months to make sure my contract ends on time.. I'm now two months over and Mtn continues billing me. Guys in store say that they can't do anything because head office is striking. So I suggested putting a stop order to which he rep**** \then you can deal with the bad credit rating "??? This cannot be a legal way of doing business. Call centre does not answer and in store service is of no support? What are we as consumers supposed to do? I just want to be out of contract as per the signed agreement. I have also signed all necessary docs to migrate to prepaid but nothing is being actioned """