One Way communication

I have a weird problem. When one particular caller (on my plan) calls me, the call connects. I hear her fine, she can't hear me. I call her back and there are no problems. Both of us are on the same plan, both have Android phones. If I call her it is fine if she calls me, she can't hear me. 


I've called tech support and was supposed to get a call back Saturday but never got one.