easyJet seem to be adept at deflecting claims for missing or damaged baggage. The baggage handling desk at the airport may direct you to the easyJet customer service desk, who may then tell you to go online. When you do this, you'll find instructions on what to do if you've filled in a form at the airport, but not much else. If you ring them, they might eventually tell you the website on which to file a claim.

Or...

Just go straight to the website. It's https://www.easyjet.airlineluggageclaims.com/

You don't need to fill in anything at the airport beforehand. Just make sure the claim is made online within 5 days of the flight, and send photos of any damage if you can.