How/where were you guys able to contact IronSource? I'm having the same issue with the Idle Heroes offer, about 6000 crowns I'm supposed to get, and still nothing. But when I go to the 'Missing Crowns?' section I get a "Fail to parse click data" error. Very annoying.
In Dominations, go to the offers screen (with the list of offers and their crown values).
Scroll to the bottom of the screen and there are tiny links there. One is for "Missing Crowns?". That will open a separate browser window.
What I did at that point was to grab the URL for that page, email it to myself and open on my desktop browser. That way I could write the email easier. You can also bookmark that URL.
Here's what I would suggest: You are probably only going to get one chance at a support ticket. If you follow up with additional evidence, they're going to claim it was already rejected. Put every bit of evidence you can in that first email. Screenshots, player ids, descriptions, etc.
These guys are incentivized to reject your offer.