"Iemand heeft mijn kaartjes gestolen!"
Translation:Someone has stolen my tickets!
"Kaartjes" also translates as "cards" in English. Otherwise, how would you translate "my (little) cards" (as in business cards) into Dutch?
You're absolutely right! 'Kaart' is a word which can translate to ticket, card, and map. You'll understand why Dutch people often use 'kaart' in a compound (for example 'toegangskaart' = ticket, 'spelkaarten' = playing cards, 'landkaart' = map) ;-)