No Snack for You

Bob wants a soda/candy bar/whatever from a vending machine. He puts the dollar into the machine, it ejects the bill. He puts it back in, the machine ejects it again. Bob takes the bill out, smooths out the wrinkles, puts it back in. The machine makes a "Ka-ching!" noise, Bob is thrilled.

The machine ejects the bill again.

Eventually, Bob is ironing out the dollar on an ironing board he just pulled out of Hammerspace trying to get the machine to accept it.

And it still won't.

Commonly Played for Laughs.

Truth in Television, since vending machines do tend to be quite touchy at times.

Advertising

 * A famous Pepsi ad from the 1990s is possibly the Trope Codifier.

Film

 * In Silent Movie, there's a Coca-Cola machine that has multiple dispensers, and fires the Coke can at high speed out of whichever dispenser you aren't watching.
 * Done in Chicken Little when Runt of the Litter tries to get a soda. A particularly cruel example, since the characters' lives actually depend on the acquisition of said soda.
 * The film version of Over the Hedge starts with R.J.'s attempt to get a bag of chips out of a machine. He does get it, eventually.
 * In The Monkees' Head, Micky is staggering through a desert, nearly delirious - he finds a Coke machine out there, drops in a coin...and nothing comes out. As he pounds on it screaming maniacally, the Coke jingle plays merrily on the soundtrack.
 * Used in the short Blair Witch parody by Toxic Bag, The Bag Witch Project, in which some gamers hopelessly lost in the hallways of a convention center search in vain for GenCon. They keep moving in circles and winding up at the same vending machine, which invokes this trope every time they return.

Live Action TV

 * A vaguely similar joke occurs on Dave's World. In the episode "Cyberspace", a program is described for an evil ATM which, after the customer inserts the card and enters the PIN, gives out nothing, not even the card back.
 * In the Scrubs episode "My Best Friend's Baby's Baby and My Baby's Baby", Panicky Expectant Father Turk is given one job: Get ice chips. When the ice machine won't co-operate, he gets his hand jammed in it.
 * In the Frasier episode "Rooms With a View", when the Cranes are waiting for Niles to have surgery, Martin tries to get a candy bar from a hospital vending machine. When it jams, an increasingly tense Daphne throws a chair at it.
 * In Red Dwarf episode "Only the Good", we get a vending machine with artificial intelligence that gets angry when Rimmer uses a coin-on-a-string to get a free chocolate bar. Rimmer is unimpressed with its threats of terrible vengeance, only to get clonked on the back of the head by a flying soda can at the end of the episode.
 * On Diagnosis: Murder, this happened to Dr. Mark Sloan, and in a bit of an Idiot Ball moment he tried reaching into the machine to get the stuck snack and ended up breaking a finger.

Video Games

 * In Zork: Grand Inquisitor, part of a puzzle involves getting out a piece of candy stuck inside a vending machine.

Western Animation

 * Done in the Phineas and Ferb episode "Ain't No Kiddie Ride" with a kiddie ride.
 * The whole plot of the Veggie Tales short "Lunch: An Animated Parable" is about one of these.
 * In the SpongeBob SquarePants episode "Wet Painters", this happens to Patrick when he was trying to put a dollar in a vending machine, which is what SpongeBob is telling him not to do.
 * A background gag on Futurama features a vending machine for "Refreshing Crack". The vial gets stuck, leading the user to beg the machine not to hold out on him.
 * Done more often than it is possible to count on The Simpsons. In one notable case, Homer is trying to buy a soda with a stolen $1 trillion bill.
 * Taken to the extreme in the Sealab 2021 episode "All That Jazz", where Murphy is trapped under an Evil Vending Machine for months.
 * Beavis and Butthead try to buy pork rinds from a machine that doesn't drop the goods - they figure if they try it again they'll get two for the price of one (?!?) While Beavis guards the machine, Butt-Head cadges a dollar from an old woman and goes to get change at the convenience store. When he spots a bunch of old nachos that are going to get thrown out, he buys them all and heads home, forgetting all about Beavis.
 * This happens in the Harvey Birdman, Attorney at Law episode "Gone Efficien...t".