Leave it a few minutes and turn the inconsiderate tw@t5 in. I hate going to the cinema for that very reason.They will be dealt with or at the very least the manager should offer you complimentary tickets as a means of compensation.
Try and leave the big films for a week or so and carefully reconsider if your aiming to go peak times,you,ll find once the 'masses' have had their fix you are at ease to enjoy the film in peace. There's nowt better than a virtually empty cinema lol.