Wages not paid from previous employer.

I gave my two weeks and served them at my previous employer. Upon receiving my last check it was far less than I was owed. I contacted the owner and he stated he was recouping a bonus that was paid out a month earlier. He said it was un earned. I did earn, hence I was paid for it. I filed a complaint with the TN Dept of labor. I was told it was basically a He said-he said situation. The owner provided a supposed document that was from the review, however there was no signature from neither him or myself. So it was something he created after I filed the complaint. I want to know if this is something I should pursue or if I would be wasting my time. I do have a limited amount of evidence, since I left that job and do not access to the files or emails. However, I believe the biggest thing is the owner paid of the bonus because I had earned it. If I hadn't - he wouldn't have paid it to me.