JBL 510BT Bluetooth Failure - No Connection or Red Charging Light

I purchased my JBL 510BT headphones around 2023 through Trendyol and had been using them without any issues until now. However, today they suddenly stopped connecting to my Samsung S21 phone and other devices I tested. The blue light on the headphones turns on, but the connection does not occur. I tried charging them, but the red light does not appear during charging either. Other devices can connect to my phone via Bluetooth, so the problem is clearly with the headphones. They have not been dropped, exposed to water, or subjected to any damage. I am not sure whether the warranty period has expired, but I request that my headphones be repaired or the issue resolved as soon as possible.