Airtime subscription still not cancelled!

Good day

My wife and I have been trying unsuccessfully to cancel the Cell C airtime subscription on his Edgars account, for over a year now. We have gone through the call centre several times, where we are given a reference and told that people will get back to us, which never happens, and then the money is deducted from the account for another month! We have also gone in store, where they phone in and cancel, get a reference number, and again nothing happens and it is yet again deducted.

Why is it so impossible to cancel this??

Please please cancel this. This is money being completely wasted on a number that no longer even works.

I would appreciate assistance in this regard.