To enable testing cheats and reset you sim, thus getting them unstuck from wherever they are (in my case it was the merchant in the forest), you have do edit a game file, it is no longer done through the cheats command prompt (crtl, shift, c).
Here are the instruction to enable testing cheats:
1. Go to you game installation folder and into the following folder
C:\Program Files\Electronic Arts\The Sims Medieval\GameData\Shared\NonPackaged\Ini
2. Open Commands.Ini with notepad or another text editor and change the following
TestingCheatsEnabled=0 to TestingCheatsEnabled=1 then save the file. If you can't get the file to safe due to access permissions. Save in another location such as my documents then copy the new file over, replacing the old one.
3. Start your game, hold down shift and click on your stuck sim. Click Object, Then click Force Reset. Your sim will now still be in the same place but when you tell them to do something they can actually move.
That's it.
Good luck and have fun.