They dismissed my debt collection case, is it really over?

Read the exact wording before you celebrate. "Without prejudice" means they're free to bring the same case again down the road, nothing's actually resolved for good. "With prejudice" closes the door permanently on that specific claim.

If you're negotiating any kind of resolution, push specifically for "with prejudice," and don't settle for a verbal promise that it's handled. Get it in writing, since a case that's merely paused rather than genuinely closed can resurface when you least expect it.