Tangential story...

I had a Northwest Airlines VISA card in the early 2000s.

One day, I noticed a USD $6,000 deposit. I sent a message to customer service that something was wrong.

The next day, I noticed a $5,800 withdrawal. At this point, I called customer service.

They removed the deposit right away, but I had to engage repeatedly to get the withdrawal off my statement. I think this involved some kind of written statement.

I've also had Discover call me, asking if I ordered a $1,200 television off Newegg, and they sent me a new card when I replied that I did not.

I have no idea what happened in either case.