Mel(posted 7650 days ago)I would go along with Mark's advice.
Have you SARN'd them yet...even though the property is not sold the SARN info might be helpful at this stage possibly.
Personally I would keep my letters polite but to the point...there is no point in getting "stroppy" with them.
Don't let on that you have family willing to help....they would have you sell your granny to get their money.
Don't panic....there is very little they can do to you at this stage and most of us have lots of letters threatening court action within 14 days...don't be intimidated by them.
Good luck and let us know how you get on!
all the best
M