I broke a game i rent what the worst thing they can do to me?

i went to blockbuster and rented black ops and when i got home my mom called me and ask me to come over to her house for supper so i put the game on my gaming chair and left and when i got home i forgot where i put and i sat down can crunch it snap in half and i broke on money right now what the worst thing they can do i was think about just sending it back and never go to blockbuster agein so i was just wondering what the worst thing they can do