Cancellation of contract

I have a current contract with cell c for a pocket router they offered and I took . The router did not work from day 1 , I called the call center the next day and advised the router isn't working / connecting . I was passed from one department to another with no proper feedback or response . A week later I was told to take out the sim and put it in my phone to check if its working by searching on the internet , done that and confirmed that the issue wasn't the sim card but the router . I was given links / sites to try and resent the router or the password still nothing . Two weeks later ( I'm the one calling them they do not come back or call me back ) I called and requested for them to take back the router and cancel the contract . They arranged for pick up a week later I gave back everything and the sim . I received a sms that they will be debiting my account for the router,I called them they advised it shows that the router was booked back for repairs (repairs for what ?) laid a complaint for bill dispute and cancellation of contract with the references Cancellation-*** Bill dispute - ***. No feedback till to date , visited two cell c stores advised they can not assist . I wrote a review on the Facebook page and was called , explained the situation the lady then told me I will charged it R4200 for cancellation as I returned the router after the cool off period . She then said they will rather discuss the refund for only Nov & Dec 2023. 24 hours later no call or feedback provided ! It's the inconsistency and incompetence that irritates me. I DO NOT WANT THE ROUTER ANYMORE AND I WANT THE CONTACT TO BE CANCELLED. I WILL NOT PAY ANY FEE ! Why wasn't it noted that I would call for more the 4 times a day trying to arrange for the router to be returned and cancelled on my name now I need to pay for a router that was returned two months back .