Received an email that my Gold’s gym membership is going to collections.

I called to cancel the membership months ago, and even appeared in person to cancel it, but apparently they’ve continued to attempt to charge the card it’s on the entire time. I’d really rather not pay the balance they’ve charged me with since it SHOULDN’T be there in the first place. What actions can I take here?

Edit: Thank you to everyone who commented, I didn’t expect this to blow up so much, especially after I had got it sorted out. I was bamboozled by the front desk CSR who told me the account was closed, so it was in fact just scummy gym business practice. I of course never checked my email or anything, and just went about my days. I wasn’t using the bank account it was tied to anymore, nor the email the bank account was on, so I never noticed them attempting to charge me. It is all really just my fault for not being more thorough, lesson learned.