Possible Wrongful Termination?

I just got fired from my employer because I was accused of making a threat to another employee. I never made this threat, nor do I recall saying anything similar to this. I have 2 work friends and only speak to them and they also stepped up and wanted to let it be known to the office that I never said that. I was accused of saying something along the lines of "I want to punch her", referring to another co worker while in a conversation with someone else. They said I said this several times, which I did not. I asked if there was any evidence and was told "no. The source who said this is reliable"... most likely a higher up. I'm not sure what to do because I insisted that I never said that nor would I. I'm now out of a job and it's so frustrating because they said I threatened physical harm when I didn't.

Is this even worth pursuing or anything that can be done about this? I'm not sure how to go about this.