Iphone 4 audio recording and/or playback issues?

Hello,

I recently purchased a factory refurbished Iphone 4. Right away I noticed while face-timing that the other person couldn't hear me and instead got a static sound. I then tried a phone call and they could still not hear me. I read up and found out it was one of the mics and I sent it back to the company I bought it from to fix it. When I got it back it was still not working! I then noticed they had tested the mic in the voice memo app so I tried to do the same. The app showed that it picked up my voice and did record. But when I went to play it I still heard nothing! I tried emailing it to myself and even on the phone you could then hear the voice recording through the email just not on the app itself. I have not been able to try a phone call yet as I want to make sure I can fix this before I set up the phone all over again, I also have not face-timed yet but I have tried it with snapchat and it still will not work.

I have read up more and have narrowed down that it is probably the noise cancelling mic and i tried the quick cleaning fix and still nothing worked. But it looks like this issue still doesn't explain the issue on voice memo with play back.

If ANYONE has ANY idea what I should do next or how I could fix it please let me know! I would like to be able to use the phone I paid for! Thanks for your help!