Cancellation of a contract.

Sometime last year one of Body Lab's consultant ******* my husband to enter into a contract with them. He was told that they will debit his account until the contract expires which will be after 12 months. Some months they just took two payments of his account then he had to go to the bank to reverse the money and pay banking fees. I phoned them a few times regarding this matter then they will just say sorry it won't happen again. It went on and on. After the twelve months he personally gave them a letter to cancel his contract because it expired. The next month they deduct again the monthly fees. I went into their office to sort out this problem. Again they told me they did not received a cancellation letter. I told them we came in to the office to give them the letter. Again we gave them another cancellation letter. We stopped the debit order by the bank. Month end they contact my husband to tell him he needs to pay a certain amount because they did not received two payments for the period his contract was still in place. I have send them the proof then the lady told me o' no its not two payments it a cancellation fee. On 22.02.2018 I got a sms from Body Lab to say that my husband owes them R787.33. They keep intimidating me that is either he pays the money or they will blacklist him. May please be assisted so that the membership could be cancelled.