Fortunato kept hurting him over the years and Montresor kept saving his anger for all that time.
Climax
Fortunato kept hurting Montresor and making fun of his family's proud name, until Montresor couldn't help it anymore so he made a plan to get his revenge.
Falling Action
Montreso lures Fortunato into his wine vaults to taste the wine and Fortunato is already drunk.
Resolution
Montresor and Fortunato drink the wine he used to lure him in to the vault.
Montresor traps Fortunato in to the wall by using bricks to build him in to it.
He finally gets revenge than leaves him to die alone in the cold walls of his vault.