Hi there! Only Customer Care can check and give back any steppingstones that you might have lost due to a technical issue that was out of your control. Please check #customer-care on how to reach out to them. 🙂
#i lost my stepping stns
normal sluice
In general (and for the future), when someone loses items (dragons, consumables, etc.) or currency (gems, event currency, etc.) they'll have to go about reporting the unfortunate occurrence to Customer Care as they're the ones who have the necessary means to check and return missing stuff.