I had the exact same thing happen to me, AWS did delete half of the charges, but still left me with 700$ on the account. So obviously, now AWS isn't my first go-to place to do business.
I did gcp tutorial that left some resources running for a month. I eventually got charged around £300, I was able to talk to a human being and they sorted it out and refunded me. So they're still in my good books.
