I don't get it. Seems like you found a fare you couldn't replicate, which I'm sure has happened to all of us, myself included. You called to try and get it matched, couldn't, got charged, then got refunded the full amount with no penalty.

Sounds like a win here man. You didn't even really have a case that the agent was rude to you.

1) Often those flight finding services find something, but by the time it's posted the deal is dead.
2) You can't "trust" google flights. The only thing you can trust is the price the websites give you when you go to pay, because google flights doesn't SELL you anything. I've found so many prices of flights on there that turned out to be meaningless. You try to find it elsewhere, then when you can't, you move on.
3) If you thought you had found a great price, you should've tried it on AC.com, if you got it to price anywhere close, should've pulled the trigger FROM the US version of the site, on the spot.

The AC site, much like UA and others offers multiple languages, countries, currencies etc. It's based off your ip's location. You can select other regions, you can use a VPN, but all that does is often wreak havoc with the site. My work computer (in canada, not VPN, canadian based company) seems to have the AC site defaulted to FRANCE, no idea why, but it's always important to check the currency on the page and all that info.

Again, I'm not saying "this is all your fault you're an idiot", but it really seems like you came away with a win here. You tried to buy something, got your money back, no one got hurt.