Chosen Solution

I can hear people who phone me but they cannot hear me and the microphone icon has line through it

Hi, Check that the phone is not ‘muted’. (you can still hear but cannot be heard) Make or receive a call, hold the phone away from your ear. The screen should light up and there should be some option icons appear. Tap on the microphone icon to unmute the phone. If you wish to mute the phone again for whatever reason just tap the microphone icon again when on a call.