Cancelled contract 6 years ago still billing me

I had a planet fitness account with the branch off jan smuts road jhb many years ago, which was cancelled almost immediately all those years ago, within a few weeks. Debit orders continued coming off my account, kept phoning and fighting and getting assured it would stop. Then about 3 or 4 years ago I wrote on here and they stopped debiting my account for a while. Its back again, I keep having to reverse the debit orders etc, and its affected my credit record as I keep having unpaid items (as they debit on any day of the month, sometimes more than once in a month) and this is totally unacceptable. If this does not stop and does not stop immediately I will be going to court, and I will find all the other hundreds (if not more) people and we can create a mass action. I am sick of this. I have phoned on numerous occasions and keep getting told they will investigate and stop etc. No I do not have the old contracts etc any more, this is over 6 or 7 years ago!!! I do not have an active planet fitness membership. I don't have a card and I have only ever used their gym once or twice before cancelling all those years ago.