can I get in trouble for making a face book page to hate on a business?

[The Phlebob]

You don't own the page. You did it as "work for hire" and your ex-employer owns it, regardless of whether you were paid for it or not or where you did it. I've done contract programming on my machine over the Web and unless I negotiated to keep certain rights beforehand, every line I produced belonged to my buyer. You may not even have the right to take it down, despite your warning to them.

Sue them for the money you feel you're owed. Keep the nasty emails as evidence (I HOPE you didn't delete them in disgust; your ex-employer made a huge error if they admitted anything in them). Realize, though, that warning you about taking you to court isn't considered a threat in the legal sense.

Consider Small Claims Court, where neither side can be represented by an attorney. These courts have caps on the amount you can sue for, usually in the $3,000 to $5,000 range, depending on the state, and collecting on a judgment can be iffy, but they are less expensive.

Good luck.