Nissan Qashqai Rear Brake Disc Metallic Noise

I own a Nissan Qashqai and for about three years I have been experiencing a metallic noise coming from the rear discs. This sound continues and negatively affects my driving comfort and confidence in the vehicle. For this problem I went to Nissan Balıkesir Ak Oto service. Despite this, I have not been given any clear explanation or solution about the cause of the noise or what will be done, and no action has been taken so far. I have not made any payment related to this issue. My vehicle plate number is 10YD9**. I request that the source of the metallic noise from the rear discs be thoroughly examined and that the necessary part replacement be carried out under appropriate conditions so that this chronic problem is definitively resolved.