Dec 16, 2016, 00:5712/16/16
Look in the top left corner of your screen to see if your total number of troops has changed. If not then it means they're not lost, and you should check your tracking and garrison tabs in the command center to see if you can find them.
Otherwise, you'll have to submit a ticket to support so they can check your account. https://support.plarium.com/entd/Tickets/Submit/Category/20