Contract cancelation

I took a cellphone contract with cellc August 2018 for 24 months and now the contract should have ended and but cell c continues deducting on my account and I have been sending mails for contract cancelation but No1 cares to reply to me and when I call in I will hold for more than 10 minutes until my airtime runs out I am fed up with Cellc and now they are telling me they will continue deducting until December I WANT MY CONTRACT CANCELED IMMEDIATELY AND I WILL NEVER EVER RECOMMEND CELLC TO ANYONE