Dear Ms. Landlord,
I have always been relatively satisfied with you as a landlord. And I dare to say we were very good tenants. We left that house cleaner than it was when we moved in, and you complimented me on that fact when we did our final walk-through FOUR WEEKS AGO.
I know there are new tenants living in that house. So WHY ARE YOU HOLDING OUR DEPOSIT?!?!?! This is outrageous, and I want that money NOW! Do you hear me?
I have put my husband in charge of the task of communicating with you on this matter, but hear me now - if I have to take this up myself you will wish you could deal with him. He is being far too nice and far too patient with you if you ask me.
I will be back in town Friday night, and if need-be, I will be on your doorstep. I know I seem so nice and quiet and polite, but trust me, there is a side of me you don't want to see, and I will get it out if I am forced to.
My money - in my mailbox - tomorrow - or you will wish you had rented that house to a rock band with a destructive streak - are we on the same page?
**Update: The check arrived today. I guess I told her! And a note to our new landlord: Let this be a lesson to you. There's something funny about you - don't mess with me! (I have back-up!)