Poor customer service at MTN never buy anything there

Bad service from mtn so I took a contract with mtn for 5G wife router 10mbps starter router, mtn consultant called me and the offer was good i took it. it was working for the fist few month after that it started giving me problems up until it stopped working at all. I called mtn they refer me to coverage they couldn't help they sent me to mtn shop, when get there I was told to go back home and call them when I'm there with the router. i did that stll the router was not working I was advice to cancel and take another one because they cant change it. Yesterday I went to MTN mall at Carnival I was told they cant book it in and they cant cancel it because I took the contract online so I must go to Head Office to book it there or to cancel the contract. the level of poor service is on another level no one cares about complains i have sent a number of emails some without response some tells me to do what I have done already and I was not assisted.