My iPhone 12 no sound at reciever end

No idea about that.

If you meet all the requirements listed in this support page (the section "Additional Information" included):--> iPhone 12 and iPhone 12 Pro Service Program for No Sound Issues , I suggest that you contact Apple Support directly and ask them, using this link:--> Contact Apple for support and service

Regards

Giulio

Maybe you are out of the three year window?

I have the same issue. Documented as being part of the batch with the issues, but I'm THREE MONTHS past the three year purchase deadline so my only option is to pay almost 500$ for a replacement. Absolutely infuriating! I requested someone to make an exception for being just out of the 3 year window, but no help.