No One Can Hear Me When I Am Making A Call, What Do I Do?

It seems that the issue would be the microphone port of your device. What you can do before sending us the device is to first test the microphone without using any accessories, such as headphones.If you are still experiencing the issue, try to clean your microphone port. To do that, please follow the steps below:

Turn off your iPhone.
Grab a soft, slightly damp, lint-free cloth like a lens cloth or microfiber cloth.
Wipe all the surfaces of your iPhone, even those you don’t routinely come into contact with, like the backside.
If the cloth alone didn’t do the job, use alcohol or disinfecting wipes (do not use any wipe containing bleach)–again wring it out before applying to your device.
Gently wipe all the exterior surfaces of your iPhone.
Let your iPhone air dry.
Use a soft-bristled brush/ toothpick/ painters tape to clean the speaker port, the earpiece and the microphone.
Turn your device back on and re-try to make a call.

If the same issue persists, we would love to look into the device for you for a repair or even a replacement.