One would think the fact that no Brazil airfare was charged to card would have kicked out a $400 charge made in Brazil in Brazilian dollars.
I don't think the above would have made any difference because some people use different reward cards for different categories to maximize rewards. I have a total of three cash back cards that I use in different places as I get more cash backs that way.
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While I agree for the most part, the card was SWIPED and still declined. Not only that, this seems to happen EVERY time I go to the supermarket... happens at Trader Joes too for some reason. Yet, when there was actual fraud on my account to the tune of $4k, they let that bad boy through without question until I discovered it.
I'd say something is seriously wrong with either your account or Chase if you're getting fraud alerts every time you go to the supermarket or Trader Joes.