harassment and intrapment

Approximately four years ago while shopping at Sable Square I saw Zone fitness holding a special. I approached one of the Sales Reps for more information and he advised i fill out their form. I made it clear that this was just informational but he still insisted me filling out their form. I was told if i call the next day before 12, the contract would be null and void. I contacted them the next day to insure this was indeed null and void and i was assured that it was. Now 4 years later after not receiving any communication from this company, text, calls etc i am being harassed to pay an absurd amount of money for a service i have never used. I have never stepped a foot in this gym yet expected to pay for a membership over 24 months and handed over to debt collecters!. After calling the head offices to resolve this multiple times (and being promised they would get back to me) and visiting their branches only to find no managers present to resolve the issue i feel exhausted and shocked at this companies business practices. I want this issue resolved immediately and it seems that this is a common practice of this company.