Membership dispute

My friend joined your gym and I asked to if I would mind trying your gym for a week which I did go to your branch in Northmead. They showed me around and told me I will have two weeks free and I just had to pay R150 for a tag. I was impressed with their equipment and the whole gym so the guy asked if I would love to join and I said to him I would rather try out the free then I would see if I am interested which he agreed but said to me they are running a promotion which means he will need my information so that should I decided to join in two weeks I will have to pay the promotion amount which I gave him and I signed. Unfortunately I got sick and had Covid symptoms which prevented me to go to gym and I even tested, the results came back negative but by the time I was ready to go gym the trail time was over so I did not go. End of July I got a bank SMS notification about R599 that was debited from account. I went there as I was nominated for a free trail and did not give them a go ahead to sign me up