Wrongfull debit after contract cancellation

I was at Southgate mall and I was approached by the Gym company sales people to open a membership with them in late May 2015. I filled the forms to apply for the membership and I was told that I had 5 days to cancel the contract and as stipulated by the membership agreement form. After 2 days I decided that I do not want to continue with the membership and I want to cancel. I called the manager to enquire about how to cancel the membership. The manager told me that I should come personally to the branch to cancel the gym contract. I physically went to the branch before the 5 days stipulated for cancelling the membership. I cancelled the gym contract and I was told that the contract I had with the gym was cancelled. I was surprised when my account got debited in July and in August. I went to the gym to tell them the problem and they are saying that my gym contract was not cancelled. I was told that I need to pay a cancellation penalty fee or find someone to take over my contract with the gym. I do not understand why I have to pay for the contract which was cancelled in a legit way. The annoying thing with the gym is that there is no accountability with the gym. Everyone is passing