Wiktionary
get back at
vb. (context idiomatic English) To retaliate; to take revenge.
Usage examples of "get back at".
Well, it took us a million years, but we finally figured out a way to get back at you!
I know jolly well you're jealous of me because Miss Willcox likes me better than she likes you, and you're trying to get back at me by hiding my things and making silly bits of trouble for me!
I ain't sure, for she don't open the blinds in that room till I get away in the morning, and she shuts 'em before I get back at night.
They might even try to get back at the others, which would incite those Ajahs, and .
Not that I was frightened of what Miplip might do to get back at me.