Teleperformance review: Final pay

I was harassed by a staff asking or notifying me to pay difference of the deduction of my final pay for a headset that as per them I lost or did not return when in fact my supervisor had received it. I let him sign a receipt and provided that to the HR-shared representative to which they did not take me seriously even said they filed a claimed/dispute and was escalated and was denied. I've provided to them further evidence supporting my stand that I in goodwill returned it back to my supervisor. Took several months before they deemed it invalid deduction after asking from their side proof and people whom they said had investigated the allegations because they've had nothing to show from their side or name the people who claimed I lost or did not return it. And up to now its running 5 months excluding the 14 months from the date I returned and last day of rendering my last day of one month notice and it is still not closed/finished. I just want this to get over so I would no longer need to hear from them. Also, I'm sharing this so that the higher ups can do a formal investigation as I've heard in the net and an employee at the cafeteria while I was still working for TP IT Park Cebu that this has been going on for quite some time and I thought it was just bad publicity, but it is true as it happens to me. Also I have a former colleague who worked for TP before she worked for Amazon captive site, my first local job in the Philippines, she left because dispute of pay and she left without getting her last pay.