But, the original creditor submitted a year's worth of statements and an agreement which stated that use of the card is acceptance of the agreement. The OC also submitted an affidavit from a person of knowledge of the account attesting to the records of the delinquent debt.
Pretty strong evidence.
If you are dealing with a JDB then they will not likely be able to come up the year's worth of statements nor an affidavit from the OC.
You must first find out who the collector is that may be suing. Is it the original lender or has it sold the debt to someone else?

