Same here. Two different vaults, weeks apart and different versions of the game...same issue. Game crashed right after buying a load of lunchboxes, phone restarted, vaults gone, vault save file now 0kb.
It appears the Android version of FS is beta and not stable, certainly not to be charging users for in game content.
Your vaults are stored locally on your phone so they are gone along with any mr handy and lunchbox purchases. (Also read reports of cloud games being nuked too).
Bethesda doesn't seem to be at all bothered and taking notice so only one thing left to do, complain to google and get your money back people!!
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Fire up the game, click on the cogs in the top left corner, then click 'i' and then help.
Select Fallout shelter -> android -> proceed
Then search for 'shelter help' . It should find the article: 'what should I do if I experience issues with fallout shelter'
At the bottom of the article is a link for android -> google store.
Here is where someone can actually help (thanks google).
Verify your account details, say you want a refund due to the app crashing or in my case in app purchases did not work, then just include the order number you were sent in the purchase email and submit!
Did it this evening and happy to say my money back in my account in under 30 mins. All credit to google.
Bethesda....shame on you. This is serious a BETA app!