I would urge you to check out the statute of limitations in your state for written contracts. Ten years seems like a long time for a creditor to have the right to bring suit against you. If they sue you, you have the right to present any defenses you have & to make the creditor prove that you owe the money.
Do not send even a token payment or acknowledge the debt until you meet with a local attorney for complete advice. Hope this perspective helps!
I would say that you certainly don't owe the money. I know of no state with a 10 year SOL on a civil suit. I would certainly not agree to pay them anything, and I would deny owing them a dime. Dispute the debt and demand a full accounting, then see if they follow-through on their improper threats.
This answer is not to be considered a response to a specific legal issue in a specific jurisdiction - it is to be considered only a general response to a hypothetical scenario posed by the questioner. For specific legal advice, please consult with a licensed attorney in your jurisdiction.