Cancellation nightmare of a greedy company

Please never ever do business with Virgin active they are money monger *****s. So 4 months ago my child which was 17 at the time said he wants to gym at virgin active , I sent a request and the marketing person phoned me and was told its R320 a month for him and has to pay a starting fee that I did . When he turned 18 the rate went up to R550 not that I agreed to that. I never signed a contract , now that I want to cancel , They want me to pay R3700 for cancellation fee. That I get nothing in return. They trap you under an contract not that they are providing any service what so all , its not a service its a membership . They ***** peoples money and they greedy. Never in my life will any person i know join virgin active or associate with them again.