Maybe I can help. First off, do you know if the debt is still within the SOL or the CRTP? What is the DOFD of the debt. You need to know this because it will determine the course of action.
If it is outside the SOL then you can't be sued for the debt, they can still try to collect and they can post to your CR. If you were to send a cease and desist letter to them and it is still within the SOL then you give them no other choice but to take you to court.
If it is outside the SOL but still inside the CRTP, they can post to your CR but can't sue you for a judgement. Posting to your CR and contacting you about the debt is all they can do. If you were to send a cease and desist letter they could not contact you about the debt, but they could still post it to your CR. A cease and desist only means they can't contact you, doesn't mean they can't contact 3rd parties such as the CRAs.
If it is outside the SOL and the CRTP then you can send them a cease and desist letter. It would be too old for the to post to your CR and they couldn't contact you for the debt.
The DOFD is what sets the clock for the SOL and CRTP. The SOL varies by state so you would need to know the particular one for your state. The CRTP is 7 years + 180 days from the DOFD. To find this, EQ will list the DOFD, TU and EX will have the date this is expected to fall off. You would count back from that date to find the DOFD. If it is not on your CR, then you might have to ask them for the date.
I hope this has explained it for you. If you have any questions, please feel free to ask. Good Luck!
July 2013 score: EQ FICO 819, TU08 778, EX "806 lender pull 07/26/2013
Goal Score: All Scores 760+, Newest goal 800+
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Current scores after adding $81K in CLs and 2 new cars since July 2013
EQ:809 TU 777 EX 790 Now it's just garden time!
June 2017 update: All scores over 820, just pure gardening now.