Disgusting Servive

I bought an MTN handset on the 25/07/2015 which was ****** from me on the same day. I've e-mailed documents, faxed and called MTN numerous times since then to blacklist it and get a ref no inorder to open a case but no one seems to be interested in assisting. Each time I call, I'm given incorrect info and false promises or a non existant number to contact. I'm disgusted by their service for a company of their magnitude. I think they are lazy and don't Care about clients. Even their teamleader cannot take ownership in resolving or escalating queries.