iPhone microphone not working

[GGbogshee]

I activated my SIM today in my daughters iPhone 7plus and now FaceTime calls fail as well as no microphone so we cannot hear her on calls.  Even tested making a video and a voice note and no sound is recorded.

Checked all settings with apple today for over 2 hours and they don't know what  the issue is?  Any other ideas? 

[GD1]

@GGbogshee If the phone is faulty you will need to call Sky or maybe drop it off at an Apple Store?

You can call on 150 from a Sky Talk Line or Sky Mobile.

If you haven't got a current Sky Mobile or Sky Talk this link should help:
(UK) https://www.sky.com/help/home Scroll down and click on ‘Need more help’ and it provides a 0333 number
(ROI) on the same link change the flag in the very bottom corner to the ROI flag to obtain an 0818 number.

Stay on the line and don’t hang up if prompted to. Apparently the quieter times to ring are just after 7am or about 9pm.