Taken to debt recvery with NO contract,ID docs

I have been called on numerous occasions by planet fitness, telling me of an outstanding amount that I have with them from a contract signed in 2007.This is all good and well EXCEPT that I have never joined any planet fitness and I was currently with Virgin active at the time. I have asked them to email me copy of my ID as well as any other documents they have supporting that I have entered into a contract with them and still nothing. I have explained that I had my bag ****** and reported it to the police. They have no record of me ever using their facilities and I don't even appear on their system .I do not own a gym card either. <br> I had been receiving no joy from planet fitness and had been taken from pillar to post, when I asked them for a contract they would take my number and never get back to me, which prompted me to complain on the (Get closure) where Jane Young the then CEO attempted to assist me on the 12th July 2012(4 years ago) .She indicated that they could not find my contract and only contact details. And that she was left to assume that one of the workers had inputted my details Which they probably received from promotional material. I recently got contacted by Saya