MTN TOOK ROUTER BUT NOT CANCELLING

I made a big mistake taking a 5g home router from MTN. I was told its unlimited data and that I can use my 2 TV and cellphones. Only to find out I can only use 1 TV on the router and it has a limit of 100g. The router also overheats from day 1. And I was also sent from call centre to store to Rica the Sim when I received the router. MTN has no structure. There is a BIG DISCONNECT and it affects us as clients the most. Reason for my complaint is that I CANCELLED contract with mtn ,I was advised to call mtn and cancel, when I called in I was told to go to the store with the router and I went. I went to mtn beacon bay retail park east london store. They gave me a form to fill in and took the router. I was then told to by the store to call customer service again to "confirm cancellation" I did that and was told to go back to the store coz theres nothing on the system. Im so tired of this place. Currently they billing me for March and April bt I don't even have the router anymore. I just want to get out of this mess im in with mtn and for them to update my credit report. Please help me a nice guy names Caleb at mtn retention tried to assist me and opened a SR Service Request Number: ***. Please can someone sort this out for me as I have ZERO direction.MTN NEVEEAGAIN! My id number is *** 087