I ended up having to send my phone to ZTE for repair. They fixed it for free because I only had it less than a month, I just had to pay to ship it there (like $7 from MA to TX). They had it for about a week. Before I shipped it though, I called Metro and explained my situation and asked them if they can temporarily hook my old phone back up again while this one was getting fixed.. they did it fast and free of charge. :)
Long story short, I got my phone back and all worked well for over a month. Until one day I went for a run using a running app that tracks my progress. As soon as I started using the app, the pausing problem came back. Worse than it was before! I thought that maybe using GPS did something to the phone since the problem came back the second I used it again (I had forgotten at the time that I had already used GPS since getting my phone back), so I downloaded an app called GPS Status and clicked Reset GPS. I haven't had the problem since. I can't say for sure that's what fixed it (in fact, I'm highly skeptical), but I figured it wouldn't hurt to share what helped me this time around.
In the meantime, I had contacted ZTE again and they opened another repair ticket for me.. they were willing to take the phone again. Which reminds me, I have to email them to let them know I'm holding on to it until further notice! I want to leave that option open for myself.
My initial request to ZTE was sent through their website, but I think you can email them directly at: email@example.com.
Good luck guys!! I know how INFURIATING it is!