Hi...im using iPhone 12 pro max... I got an issue with phone... My mobile data won't work properly.. Once I update to i0s15. 2 its get more worst... Lacking and can't read my sim... What to do on this issue..??
iPhone 12 Pro Max, iOS 15
If you already took your phone to an Apple Store then their verdict cannot be tested here, you will have to go to Apple Support for further adjudication.
Depending on your region, you may be able to reach them here: contact Apple Support