Messing up my credit Score

So I signup for black tag with Planet Fitness and I chose to pay in the club (Debit/Credit card). Every month end when I try to pay the receptionist would normally not be able to assist me because the system does not reflect the amount I need to pay, so we (reception and I) always wait for the 1st or 2nd then the amount reflects plus my tag gets blocked. This has been going on for more than 2 years. I would receive sms mentioning my account is not up to date, when I go to Planet Fitness they would say maybe the sms is late since the system shows the account is up-to-date.

Fast forward, Planet Fitness handed my name over to debt collectors (Nimble). I was shocked to get a call saying I owe arears from my black tag. First all all, your system NOT MINE, yours!!! Does not allow us to make payments upfront! I ALWAYS HAVE TO WAIT ON YOUR SYSTEM TO REFLECT THE AMOUNT!!! Secondly, I never received a call or email with the invoice requesting for payments which I ignored. WHAT GIVES PLANET FITNESS THE RIGHT TO HAND ME OVER TO DEBT COLLECTORS???

IF my credit score get messed up because of PLANET FITNESS??? I will definitely take legal actions against you.

GET YOUR NONSENSE RIGHT