MTN no assistance

I was phoned by MTN beginning of October with a deal on a router. I app**** and the router was delivered, it worked for about 5 days but since then until now almost 2 months later there is no internet connection. I have send numerous e-mails to no avail, I even reversed my dt order and within days received a demand letter from MTN? Now my account is paid in full again but no service for over a month and absolutely no assistance. It seems impossible to get out of the contract as well as impossible to get someone to assist with the connectivity of my router. Is there any manager out there that can assist in this matter.