PFD for less than amount owed - any success?

[azsassycat]

I am thinking of sending a PFD letter to a CA for an amount less than what is actually owed on the account.  Has anyone done this successfully?  What wording to you put in your letter to make sure the CA doesn't "sell" the unpaid balance of the account?

Thanks for the help.

Cathleen

[Anonymous]

Whatever you do you know to get whatever they agree to in writing.