Failure to cancel device as per request

I asked for an early termination fee and the amount required for early termination, I called in on the 23rd of June and paid on the 26th of June and after making the payment as per their quotation, now they refuse to cancel my contract, requested for call recording to be listened to and for the cancellation to be processed, to date none of that was done. They are basically forcing me to continue with my contract unwillingly. I’ve been their customer for for 5 years but currently I would never recommend anyone to use their services.