Clone items

I played minecraft pocket edition and i breake 4 block and i put the 4 block in overworld an place chest after i open ches and close chest and i save and quit and wait 15 second and again i m entering my map and i open chest put the items and breake 4 block and wait 4 secon and close the game and wait 12 second again entering the game and entering my map after my items in my inventory but same items in the chest.