It means you set up Mr. Krabs. You stole the crown so Neptune would freeze him and you could finally get your stubby little paws on the Krabby Patty formula.
11 seconds sound clip from the The SpongeBob SquarePants Movie (2004) movie soundboard.
You can hear this line at 00:38:54 in the Blu-ray version of the movie.
Quote context
[...]
- So... You're selling Krabby Patties, eh, Plankton?
- And there's a free bucket helmet with every purchase.
- No.
- And what's that supposed to mean?
- It was you all along. But you made one fatal mistake. You messed with my paycheck.
- And I'm gonna report you to the highest authority in the land, King Neptune!
- We'll see about that, Inspector Looselips.
- Now activating helmet brain-control devices.
- Huh?
[...]