iPhone 11 Pro Max FaceTime sound issues

Why is Apple not fixing or addressing the sound issues while on a call or FaceTime???? This is BS!! People paid a lot of money for a faulty device that Apple say works fine and will not replace. I wasted a lot of my time trouble shooting the issues with Apple and they refuse to admit that the 11 and 12’s are garbage. To top it off the tech clearly heard the issue but the diagnostic test came back with no issues, so he stated due to the test results Apple will not replace the phone. The tech even admitted that Apple knows about the issues. I’ve been an Apple customer since day one, and this is the last time we spend any money on an Apple product.