Relief!
Okay, EA Customer Service finally felt sorry for me, I guess. Here's what has happened (screenshot attached for reference):
1.) Unprompted by EA, I uploaded the transcript of the PlayStation Customer Service chat where they told me they wouldn't refund my money. When you chat with PS CS, there is an option to save the transcript. Save often, because as I indicated in a previous post, the PS supervisor I was chatting with abruptly closed the chat on me.
2.) Unprompted by EA, I uploaded screenshots of the Coin Packs that were listed under my "Services List". This section can be found on the PS4 under Settings -> Account Management -> Account Information -> Services List. Under Services List, you should see your PS4 games, including Plants vs. Zombies: Garden Warfare 2. When you click on it, you'll see all the content you've purchased for the game. I have one entry each for each TYPE of coin pack I bought: Epic and Modest. I DO NOT HAVE multiple Epic entries even though I've bought multiple Epic packs - multiple purchases seem to be filed under one entry.
When I clicked on the Epic Coin Pack entry, it showed I had 2,330,000 coins REMAINING. Obviously, they weren't used. There was another pack, Modest Coin Pack, that I don't even remember purchasing that had 120,000 coins REMAINING.
3.) When I called EA Customer Service, the CS rep ("Level 1", if you will) reviewed the case and saw I had already been referred to a Tech Specialist ("Level 2") a couple of days ago. I mentioned the PS transcript and he reviewed it. After he reviewed it, I mentioned the Services List screenshots. He was seemingly unfamiliar with this bit of info and seemed surprised. He bumped my case up right after reviewing those screenshots to an EA Help Specialist ("Level 3"). He told me to expect an e-mail and not to worry.
Just a few minutes later, I received an e-mail from the EA Help Specialist who said he credited my account with four (4) packs of coins which would be available the next time I signed into the game. My son and I signed in and, sure enough, there were four (4) coin packs in the sticker vending machine.
I don't recall how many coins we had before we opened the packs (perhaps 200,000 or so), but I ended up with 1.9 million coins plus. That's not as many as what the Services List says I had remaining, but at this point I'm fine with it. Rux amazingly offered the last piece of the Disco Chomper again this go-around, and we bought it. We now have everything but the Unicorn Chomper.
Hope this works for you all.