Membership due on a non existing account

I received the following message from Jet e.g. 'Hello L... E.., your Jet Club membership fee is not up to date. You could lose your Jet Club benefit. For queries, call IUA on ***. T&Cs & std rates apply' - Although I had an Edgars account which I closed months ago, I have NEVER had a Jet Club membership. Where on earth did they get their information and how will this affect my credit score? How can membership be due on a non existing account?