?? Donation

I had 300 coins.. I spent it on a donation set once I refreshed my paged it says I have 0 coins? I have screenshots of what I purchased and the coins I have left.. When I tried to buy Pony sg it says You do not have enough coins to buy this item.

I bought 1 donation set and it duped 2 more and took my extra 200 coins away wtf is happening :(?

Proof :
http://imgur.com/LyT2UR6

Refunded.
This happens when you buy something and press the previous page button, which makes you go back to the page to buy the item.