Cell C wont cancel my LTE data contract that they no longer support

I have an LTE contract with Cell C Using an LTE router which I purchased from the Cell C shop when I took out the contract. I have had not connection for over a week. I went to the Cell C shop and they phoned head office, who told themnI must hand in my router as they no longer support LTE, I did not hand in the router as that was not part of the contract. I then phoned Cell C to cancel my contract, they said I needbto log a fault first and then wait 48 hours and phone againbto cancel!! This is *******, they have already rlltaken the money out my account for September, which they need to return, I will phone my bank to reverse the debit order. My cell number for this contract is ***. It looks like Cell C is in serious finanancial problems and their service is already so poor!