bad credit written off

I joined the gym at 2009 and only attended for a week after that i could'nt go to the gym any more because my car was taken by the cops and there is no transport from where i was staying that could take me to the gym.I called the gym informed them that i would like to cancel they refused and told me i am bound on the contract for 3 years of which they never explained to me before joining the gym and i was never given the copy of my contract. they then said to me i must transfer the membership to someone else and i could not get anyone.they were always taking my money and i was not attending the gym, i ended up going to the bank and stopped the debit order. no one ever called me to ask why are they not getting the money, until earlier this year that i got the letter saying i owe them around R7000 and they want to blacklist me. When i tried to buy the flat i was told there's a default with the gym compony.