Apple - Apple not fixing my phone even though its under warranty

Hi, I recently started facing issue with my iphone ** pro rear camera, * reddish dots are coming which are noticeable while shooting in white background. I took my phone to service centre where they bluntly told me this is not covered under warranty and this happens when camera is exposed to laser. I have never shooted anything in laser lights but they did not entertain my issue. I contacted apple support online and after roughly *-* days of waiting they also came back with the same feedback that this issue happens because of laser exposure. Even the support representative was not aware of any such issue. Though I have never exposed my camera lens to laser I am asked to pay around **k to fix this issue even though my phone is under warranty. please help, my apple case id is ************.