PDL Cease & Desist?

I checked out the Cease & Desist letter, which was geared towards CAs, is there something similar for PDLs? I got yet another notice from Interim Cash Ltd., and am now at the end of my rope. As I have mentioned in previous posts, I have already paid $632 on a $200 loan. Interim said they would settle with me for $250. I was so tired of dealing with them that I agreed to it just to get them out of my life for good. They are so incompetent that they have been unable to successfully debit my acct. for the past 2 months now. I have confirmed and reconfirmed my acct. details, which are correct when they repeat it back. Yet when it comes time to debit the settlement amount, I get a notice saying they weren't able to because my account does not exist. Funny that, if it didn't exist, I wouldn't have been left with $50 after all the PDLs took their fees last pay period.

Anyway, I am now done! I am not paying them any more and want something I can mail or fax to them to tell them to bugger off!

Suggestions?