Plantronics Voyager 8200-UC Stereo Bluetooth Headset Problem

Hello, I am not sure I am posting in the right place, if not, I am sorry. I bought a Plantronics Voyager 8200-UC Stereo Bluetooth Headset (privately). I bought it because I was told that it can connect to two devices at the same time, for example, PC and Android Phone. For the first two months, everything worked perfectly fine, headset connect to both devices automatically after pairing and phone calls and media worked perfect in both Computer and Phone. Then a strange problem started to occurr. I lost the abbility to hear media on the phone. Phone calls continued to work perfectly, but no sound on the phone (music, whasapp voice messages, etc). In the PC there was sound. I started to investigate and discovered that if I use the headset on the phone only, I had sound on calls AND media. But whenever the computer was in range or on, no media sound on the phone. Calls still worked as usual. I contacted your support and spent a month trying to debug the issue with one of your support engineers, Armando, who was very patient and kind. Things we tried: 1 - Factory reset - didn't work. 2 - Firmware update - it already had the latest version. 3 - Completely deplete the headset battery, refill and reconnect again. Didn't work. 4 - Unpair the headset from the phone and computer. Then, repair it, BUT, making sure I pair the phone BEFORE I pair the PC. Did that, it didn't work. 5 - For a short while, if someone called me on the phone and I answered with the headset, for some reason a few minutes after the phone call was over, I had media back on the phone, together with the PC. It would last for about 10 mins and then gone again. 6 - I went to the phone settings to make sure media was on for bluetooth - it was. 7 - I tried it with a different computer and a different phone, same problem. 8 - When the bluetooth is connected on both phone and pc and I try to hear media on the phone, not only I don't hear anything on the headset, I don't hear anything from the phone itself either! It is like the phone is mute! Meaning - the sound is going *somewhere* - but where??? This headset cost me a lot of money and I bought it out of my own pocket to have the best of the best. The conclusion that the Support person got is that I have a faulty headset and I should send it back and ask for a replacement. Problem is, I bought it from Amazon USA and I live in a different country. Sending it back and then back to me again would cost me as much as buying a new headset. So I am writing here as my last resort, to see if anyone has any ideas. This headset is invaluable to my daily life and this issue is a serious problem for me. Please let me know if you can help. Kind regards and thanks in advance.