You can always take her to small claims court for the return of the TV or for the value of same, and then see what happens. But, this one is and will be a lot of he said/she said. I would not hold my breath. You were living together, but you were not married. Presumably, you both watched it while together. Ergo, marital property division rules will not apply here. Frankly, to me this one looks like something from which you both benefitted.
Given your living situation at the time, the police will not get involved.