Virgin active Accounts

I signed up with Virgin Active In April 2019. Eight months later I received a call from VVM their legal collection services stating I've been handed over to them for an amount not paid five years ago and I am to settle. Upon signing up and paying the joining fees this was not communicated and I don't have record of the cancelation letter I've emailed five years ago. My biggest concern is the manner in which I'm forced to pay an amount I've already settled and Virgin active takes no responsibility for their negligence on signing me up in the first place knowing there was an outstanding balance?