The last time I had my phone activated was back in mid-June and had it reactivated in late July. I think that this plays a part in why other people can't hear from end of the phone call. I can hear the other end but not the other way around. Although, in the past, I'd went a month with 0 days on my phone but when I added minutes it was fine. But the difference back then was I used the $30 prepaid card that keeps my old minutes while recently I started using the $25 card that doesn't keep minutes.
Could the different phone cards be a factor?
How do I fix my LG 300 so that other people can hear my side of a call.
PS: I can send text, receive text, make and answer calls.
Based on my similar experience with another phone, I don't think it has anything to do with when you activated your phone. My understanding is that you have to call Net10 to switch between the two type of airtime cards/plans, but if you can currently make and receive calls as well as send and receive texts, then my guess is that your setup is okay, but there is something physically wrong with the phone.
I had this problem with my first prepaid cell phone, an old Nokia 1100. I dropped it on the ground a couple of times. I could make calls and hear the person on the other end, but they could not hear me. I "fixed" this problem by buying a new phone. I remember this problem because it happened just before a long drive, and when I called to update my family on where I was, they couldn't hear me which was quite frustrating.
I don't think your model has a voice recorder, so you can't check if the microphone is working. other that by calling a person which you've already done. You can call customer support to make sure there's nothing wrong with your account, but unless you've accidentally muted the microphone, I suggest trying a new phone. If you haven't dropped or damaged it in some way, and it's less than a year old, perhaps Net10 would replace it under their warranty.
Sorry I can't be of more help.