3d Solid vertical "Loft" doesn't bring the best result

Hi,

I have a vertical construction which isn't orthogonal, I drawed 3 layers to use the Loft-tool via cross sections, and it works, but not ruled but kind of smooth. But I definitely need it ruled.

I somehow couldn't attach the dwg-file, so I attached a screenshot. There you can see, that the upper solid doesn't end at the same point as the lower solid (U-form). Maybe someone knows a solution (and also about why I can't attach a dwg-file) =)

thanks