> The only step OP should take is finding a lawyer that will work on contingency. There are plenty of employment lawyers who will take the case and bill you hourly, but if you can't find one to take it on contingency that is a good sign you don't have a real case.

This!

Unless you're working in a dinky little mickey-mouse outfit, I will bet good money that HR consulted their lawyers before firing. Which means we have two parties here, and one party has already been advised on a course of action by their lawyers.

It's a shitty thing to do, but my money is on the company being in the clear, legally.

You can bet your ass that the company covered theirs.