Sorry you are experiencing this issue with the microphone on your KIN TWOm! I am happy to assist.
Is this happening on all calls or after using a headset or Bluetooth device? Ensure you are not accidentally touching "mute" while on the call. If neither of these are the case, I would like to suggest performing a soft reset of the device by powering it off and removing the battery for approximately 30 seconds.
Please let me know how this works out for you!
I have a kin onem and I have the same problem. It is never on mute and I dont have a bluetooth. I have taken the battery out multiple times.
If my mic does work, it crinkles and makes static noises so much that there is no point trying to talk on my phone.