OK, let's try going back to the basics. From what I read, your troops are in a camp which is not yours.
(If you play Aragon server, some information provided below may not be correct)
First, click on this to access the valley map:
Next, let's view all of your outgoing attacks by click on this image. It's small but is located on the right side panel under "campaigns". You may need to scroll down to find it. the mouse-over show read "my attacks". You may need to click it multiple times for the list of outgoing attacks to appear below it:
From here, you can find the place you sent your army to. You can click on the name of the place to center your map on that place's location or you can click on the swords to enter the tactics of that place to access your armies in that place. Go ahead and click on the swords to enter into tactics.
OK, you should be in tactics now and you should be able to see your army. Now click on all of your armies or simply click this icon to select all of your armies:
Now click on one of the four exit points on the map to move your armies there:
The four exit points are the four spots which are different than everything else.
When all of your armies reach a exit point, click on this icon to open up the leave city menu.
When you click it, a list of cities should appear below (you may need to scroll down to find again). Select the city in which you want your armies to return to and click on "return to 'the city you chose'" button.
There! It should be done. Hope this helps.