Hello @Shaun639, welcome to the community!
I'm sorry to hear that. Have you been able to do a diagnostic test on your microphone? If you go to Settings ( > System ) > About Phone, you can find Diagnostics (Or Support) at the top, and here you can run a test to check the microphone. If it works fine here, we know that the microphone is working correctly out of a call.
You should then try to make a call while your phone is in safe mode just to make sure that no third party application is interacting with your microphone. In safe mode, all downloaded applications are temporarily inactive, but you can still use the basic functions, like calling, text messaging and accessing the Internet. Make a call in safe mode and see if you can be heard, and to get back to the normal mode, just restart your phone as usual.
Keep me updated! I would love to hear how things turn out.
