Cannot cancel my account due to bad service

I went to virgin Active bluff to join the club. The sales agent took me around the gym explaining all the equipment. We went to the office where she helped me complete the application. I gave her my contact details and bank account for the monthly membership fee. I was told I would receive the full membership document via email and she allowed another sales agent help a client open his account because it was busy and their did not have enough computers for all the agents and the new clients. I never received the documents and about 20days in the contract i sent a request to cancel the membership. Someone called me to advise me I must pay 40% of the membership due to the cancellation. I advised them no one mentioned this to me and I was never sent the documents. They sent them to me and I noticed that the email was captured incorrectly. I made them aware of this and that’s why I did not know that cancellation must be done within 5days. Now I am receiving calls from MBD legal to pay an outstanding amount of R5800 which I refuse to pay.