Minecraft Piggy Plush Bank
Ours did the same, I removed all the screws, took it apart, then removed the plug. I put the cap back on and screwed all the screws back in without the plug in, then put the plug back in. After that it worked, still a little hard for my son to open but it works. Hope that makes sense.
It's supposed make sounds when you put coins in it, if that doesn't work try changing the batteries.