MTN has no integrity and offers poor client service

I received a call from MTN offering me to upgrade my contract, I informed the agent that I do not wish to do so, he hung up on me and a few minutes later, I received an sms that my order was processed. I immediately called MTN and to my surprise, they shifted the blame to RewadsCo ( a third party that is contracted by MTN to contact MTN's clients on MTN's behalf for upgrades) after numerous of calls, I finally got through to a RewadsCo team leader who promised to investigate the matter and get back to me with feedback. The incident took place in July, today(October) I still have not heard from him. My contract finally came to an end and each time I try to contact MTN to cancel my contract the line conveniently gets cut off after they hear the reason for my call and that I refuse to take up another contract they offer, this happens each time after I have held on for 20 to 40 minutes at a time. If you choose the option to upgrade, on the other hand, the call is answered within 5 minutes. I find this to be a total disregard for people's time and poor service delivery. MTN and it's service provider*****adsCo) are dishonest and have no integrity. Deliberately upgrading my contract despite what I said, not getting back to me with feedback and hanging up in me because I wish to end the relationship.