My 2 cents

Your case is bit tricky. They made it clearly it was not performance related. Otherwise they would have put you in PIP (performance improvement program) first. They should have also documented all the communications to you before the termination. Otherwise you have the right to escalate. If it was RIF (Ruduction in Force), it is hard to argue if they follow the severance process. However, if there is no massive RIF in other Org., and you believe it is performance related, you can talk to a labor law lawyer for a free consultation. Then you figure out your chance to win the case and cost of it to make the decision. I am sorry to hear about it. But sometimes we need to learn how to let go and move on. Life is not always fair. Sometimes we can't change anything, but we can always change our attitude. Cheer up. You will find a job soon. Finance/ Accounting job market is pretty good, at least in the bay area. Good luck!