I purchased $20 = 40 lunchboxes. I used 10...when my vault was deleted...I didn't retain my 30 u used lunchboxes that I bought with money$$$

I think that they mentioned somewhere that the lunch boxes will be gone when you delete the vault.

Similar condition applies to other games with inapp purchase.

When I play those free games, I buy some in apps to appreciate the developer's effort if I like the game. It will drain your wallet if pursue for more.