Anyone else have trouble with the sound on their iphone 7? Unable to make or recieve calls!

Both my phone and my sister iPhone 7 now have this same issue. Is apple going to be offering a fix for this? We have only had the phone's one year. Anyone else with this problem? There seems to be no way to repair - apple store trying to tell me I just need to buy a new phone but I've only had this phone for one year, I'm still paying it off. Want to know if this is a common problem and thus really an 'apple' issue with how they designed the phone.