I am having the same problem with my cell phone (Samsung Galaxy, somewhat old model). I have had this problem for several weeks -- phone worked for some calls but not others (some local NYC, others out of state). Now it doesn't seem to work at all--I can hear others perfectly but they cannot hear me (problem as I needed to schedule appointment with my radiation oncologist). Before I buy a new phone I wan't to determine if this is a Verizon network issue. Maybe it's time to find a new provider.
We want to make sure that you are able to rely on your device and service, SKM21. I see you mentioned that this problem came up just several weeks prior. Were any changes made to the device around that time? For example, a new app, software update, a new SIM card, etc.? Does this happen with every call? Have you noticed it happens in one specific location or everywhere you go?