if you start your turn, but don't finish it inside the hour, then all troops not deployed are lost.There is no way for you now to get those troops back, this is a feature and not a bug.
It is called running out of time.(as opposed to missing a turn)
Missing a turn
In casual games you have 24 hours to take your turn before the game moves on. You must also finish your turn within 1 hour of starting it. In speed games you have from 5 minutes to 1 minute to take and complete your turn. Either limit can cut you off in the middle of play, so keep an eye on the countdown!
If you run out of time you will lose any troops that have not been deployed and any spoils that have not been awarded.