I ran into a similar problem with some walls I had in a project. What I did was this...
I used an elevation of the space/shape needed for my wall. Traced the outline of the shape I would need the wall to be with the fill tool (could also used line or polylines). Copied it....
Open Complex Profile and create a NEW Profile. Paste the fill you created from the elevation view and edit it if need be (materials, lines, etc.).
Save the profile, and return to the plan view.
Using the wall tool, select profile wall, and choose the wall you just created in the complex profile tool.
Place the wall where you need it to be and use the "length" of the wall as its "thickness", say 8" or whatever it may be.
I found it easier to place the wall outside of my drawing area, type in the "length (really thickness), and then drag the wall into place.
Then, open the elevation back up to make sure all edges are touching correctly, if not, edit the profile accordingly.