I had paid {$140.00} to XXXX on XXXX/XXXX/XXXX for usage from XXXX/XXXX/XXXX - XXXX/XXXX/XXXX. My last visit to the facility was well before XXXX/XXXX/XXXX. I had emailed XXXX to discontinue my membership and that I have already fulfilled my mandatory XXXX agreement of staying on as a member to avoid early termination fees. I entered into a year contract from XXXX of XXXX. I know for a fact that XXXX has a record of my attendance, and that my last checked-in usage of the facility was before XXXX/XXXX/XXXX. 

On XXXX/XXXX/XXXX, I received a letter from Dutchess Adjustment Bureau, from XXXX XXXX a debt collector ), as noted in the letter. It says that unless I notify this office within 30 days after receiving this notice that I dispute the validity of this debt or any portion thereof, this office will assume this debt is valid. If I notify this office in writing within 30 days from receiving this notice, this office will : obtain verification of the debt or obtain a copy of a judgment and mail me a copy of such judgment or verification. If I request this office in writing within 30 days after receiving this notice, this office will provide me with the name and address of the original creditor, if different from the current creditor. 

I have no idea what this means and they are trying to collect a balance of {$280.00}. Please advise on how I should proceed.