Complaining

Hellopeter I wanted to ask if this is possible i had an account with planet fitness in centurion R55 its about 2 to 3 years now..the time i attended the gym is the day when i sign up with them and the following month i relocated to polokwane due to work...now am receiveing emails that i owe them 9000 which i dont know how it came.and again they gave me a tag to tag everytime i enter the gym that will open the doors for me...so now i think those tags keep record on their system stating how many times i attended the gym i never even go there once but i owe them money how cos i never attended the gym please help.