A movie that combines Melissa McCarthy of “Bridesmaids” and Jason Bateman of “Horrible Bosses” – both stars of successful and well-received comedies – should be funny. But after two unbearable hours, “Identity Thief” only delivered unfulfilled expectations and missed opportunities.

“Identity Thief” follows Sandy Patterson (Bateman), an accountant who just quit his job to join a co-worker’s (John Cho, Harold of “Harold and Kumar”) start-up company. But the plan is stalled when Sandy’s identity is stolen by Diana (McCarthy). Diana is a con-woman who literally lives on other people’s money. After Sandy’s credit card is declined and his new boss brings up a troubling arrest record, he’s forced to take matters into his own hands.

Sandy travels to Winter Park, Fla., to bring Diana back to his home in Denver. But the plan gets complicated, because Sandy and Diana have the same ID, making airport security a problem. They are forced to drive all the way back to Colorado, turning “Identity Thief” into a road-trip disaster movie. Hilarity ensues … or at least that’s what’s supposed to happen.

Melissa McCarthy is great as Diana. You can tell that she’s doing the best she can with the caricature of a character she’s given. Diana is supposed to be loud and tacky. She dresses in patterns and blue eyeshadow and is a compulsive hoarder of things bought using the money she steals. But even with McCarthy playing the role, the character falls flat and fails to bring the laughs the actress is capable of getting.

At one point in the movie, “Identity Thief” tries to change the audience’s perception of Diana. Her character goes from a sociopath with no remorse to a flawed character who’s merely the product of a sob story. These scenes are annoying, preachy and out of place with the vulgar comedy “Identity Thief” tries so hard to peddle.

As Sandy, Jason Bateman is alright, relying on jokes that get really old, fast. The point that “Sandy” is a girl’s name is made loud and clear after about five times. The same running gags, including a story that Diana tells strangers they meet along the way, feel like Thanksgiving when your uncle is trying to make everyone laugh with the same punchline over and over again.

There’s an added subplot of Sandy and Diana being chased by two gangsters whom Diana conned back in Florida. And for good measure, a bounty hunter is also in the mix. The movie – already too long – could’ve easily done without the added twists. Removing them wouldn’t have made the film better, but at least it would’ve made it shorter.

On top of the unfunny script, the two gangsters are played by Genesis Rodriguez and T.I., who also happen to be a Hispanic woman and a black man. Of the four minority characters seen in the movie, half of them are criminals. As any communication course will teach you, that is known as stereotyping.

When Sandy and Diana’s journey finally ends about 45 minutes and too many flat jokes too late, it’s weird and out of sync with the tone of the movie. In a way, it feels like the director and screenwriters decided to change direction of the film in the last quarter of the movie. The conclusion is cliche, and without giving away the end, I’ll say the “anyone can change” lesson just doesn’t feel like it fits the movie that “Identity Thief” wants to be.

It’s a shame “Identity Thief” is such a bad movie considering what strong actors Bateman and McCarthy have proven to be. I hope the leads can find their own stolen identities, return to being hilarious, sharp performers and find material suiting their talent.