Do I have a case for defamation? [UT]

I was terminated from my job for “fraud”. The alleged fraud has to do with a referral bonus. I was not eligible for this bonus as I was in a leadership position. I had a mutual friend of this referral and asked if she would be willing to refer the candidate. This other employee put the referral in and all was well fast-forward two months I was accused of, forcing this employee to put the referral in and expected the referral bonus to be given to me once the referring employee received it. This bonus was $1500. Because of these allegations I was terminated. Fraud is now on my file for this major corporation in Utah and I will more than likely never be able to get a job here again because of that.

Another thing I should note, the dates they gave for the alleged fraud occurring I was on documented PTO out of state. I sent an appeal in for the termination describing this, and it was denied.

Do you think I have a case for defamation of character?