Bad service and bebit order after cancelation of contract

I joined zone fitness two years ago and when my contract ended they debited two more payments which I was never informed about because I didn't renew contract.so I reversed one debit order and started getting smses of arrears.i paid th balance and she canceled my contract and yet I still get smses weekly saying I owe them. When I call no one answers and my emails are being rep**** yet they tell me.

When I canceled I was communicating with zanele Simelane and Salmina sekanki.

When I query, trying to find out what I owe because my contract is canceled they don't reply or answer my calls.