Lazy Personnel

In 2021 I took out a membership with Planet Fitness. I cancelled within 5 days of signing up. Now 2 years later I have a collection agency calling to pay for a cancelled membership. After explaining to the 20th person that called me from Landou Attorneys who doesnt care about my side and just wants money. I told this person to check with their client if I ever accessed the gym or used any facilities, she told me its not her problem, I should have proof of the cancellation. How do you expect me to have proof 2 years later? This is someone at Planet Fitness not doing their job on time and now I must be held responsible. I refuse!!! To hell with paying for something I did not receive any benefit from, never used, never accessed!!!