Taking debits without authorisation

I am referring to the gym that is in Berea, Durban.

They have been taking off debits off an account without authorisation and after trying to call, with no answer, and sending numerous emails, still no answer or response, they still just carry on doing what they want to do.

The contract expired end July and they were advised in June to cancel the contract due to the person going to the gym no longer having a job so him not being able to pay. Still, they did not cancel the contract and each month tried to take off a debit off an empty account which led to charges being charged.

The people there don't know what they are doing and I am now sick and tired of this and am in the process of taking this further as no-one contacts you back or even bothers to respond to your emails.