Samsung SCH-A670

I'm on my 2nd Samsung a670. The first one was great but the hinge broke (a class problem with this phone). Verizon gave me a new one but people now complain that they can't hear me with the new phone. Verizon claims that there is no way to reprogram the phone to make the microphone more sensitive. I'm not sure I believe that. I've seen tips on this forum on how to turn up the ringer volume. Is there not a way to make the microphone more sensitive? I really want to avoid replacing the phone again because getting my data off the current phone and onto the new one is painful beyond belief, even with BitPim.