Are you seeking work in New York City? (Apparently yes. My writing was more time then the login dameon allowed.)
If so, you might look at your facts starting here:
http://www.nyc.gov/html/cchr/html/coverage/credit-history-faqs.shtml
Don't get me wrong. The letter is what many in the real world would call...stupid beyond all belief. I mean really, do you think a jury who saw such a letter would think you harmed person? One of my skills is to write letters people are interested to read and that give them a little fear in the back of their mind that they just better do what I say or they will have problems. Real problems. It's a bit of an art that combines psychology with knowledge of the law and of the specifics of the particular situation.
But, I don't burn bridges. I sell what I want to happen in a way they will agree. In fact, it makes it easy for them to agree. You? You made yourself a problem that is better to be rid of than considered. I suspect there is no way past the front where you have any claim. As to if they violated things before the barbaric yalp of stupid, read the link and let us know. Be sure to know such a petulant letter might just remove any realistic chance of a claim, even if there were a violation.
Grow up boy. No one likes fat, drunk and stupid.