Complain about the mtn contract

since I have complained about mtn contract that I did not receive my device that I am paying , I tried to call mtn and they said they cannot assist me with anything and I was reffered to mondo their sub contractors that upgraded my contract but I do not get any help from them and both of the companies I tried to call to assist me but no one is willing assist me. I even tried to send the email to mtn but still no one I assisting me until today since April 2019