MTN holding me ransom

Having complained to MTN about diabolical service and asking to have my contract cancelled at no extra cost as a result of their breach of contract by not delivering or rectifying a costly situation for me, they offered me an upgrade as compensation to not cancel my contract. When I asked for the upgrade to be fulfilled or the contract to be cancelled, as I lost my phone and needed to move forward, I have been passed from pillar to post, had no timely responses and am still waiting for someone at MTN to take responsibility and make a decision. Different people call me and each time I have to re-explain my situation. NO-ONE is taking responsibility and dealing with my situation like a proper service company should. Having provided written transcripts of the useless service I originally complained about, still no reply or resolution. Who the hell runs this place and who the hell is accountable to the customers? Dialling numbers that constantly cut off, speaking to 20 different people, sending e-mails that are not answered and being told nothing can be done, is absolute ******* and proves the shocking service I originally complained about on the 07th Oct - 21 days ago!! MTN stand up!