I've been tricked by a vending machine plenty of times.
I put the change in, I type the number of the snack, the hook starts to turn but the package stays attached...
Result, I lost my money and, in addition, I ate nothing!
Fortunately, a friend, whose job is to fill the vending machines, explained to me the trick to not be fooled again.
The reason some packages get stuck on the metal hooks is that they have been incorrectly placed in the machine.
For the product to unhook correctly, the 2 lower corners of the package must be in front of the hook:
How To
If the person responsible for filling the machine has placed a product with a corner of the package behind the hook, this greatly increases the chances that this product will get stuck and not fall.
Simply put, don't buy anything from a vending machine unless you can see the 2 bottom corners of the package in front of the hook .
There you go, now you know how to stop being fooled by a vending machine :-)
Know that it is useless to get upset against the machine, the package will not fall any more!
You simply risk damaging the mechanisms inside the machine or causing it to fall on you!