Where does my Piggy Bank money go?
The Piggy Bank does absolutely nothing but cost money. You cannot get the money back. And according to the IGN wiki it is unknown if there is a reward for putting bells in it: http://www.ign.com/wikis/animal-crossing-new-leaf/Piggy_Bank
It is a Lucky Item though and can contribute to your Feng Shui score no matter where you place it in the room: http://animalcrossing.wikia.com/wiki/Feng_Shui
In previous games it was also worth 7,777 Happy Home Academy points. But I cannot find proof of that for New Leaf but this guide suggests it is true for City Folk: http://www.gamesradar.com/cheats/16074/
Several forums posts also reference the fact that your bells are gone forever. They go nowhere:
- http://www.gamefaqs.com/3ds/997811-animal-crossing-new-leaf/answers?qid=354268
- http://www.gamefaqs.com/boards/997811-animal-crossing-new-leaf/66502880
Get the toy hammer from the gift shop and then click on it to smash it open then u get your money back and the post office sends you a new piggy bank