Extruding to one surface which is actually two.

Hi all,

I am trying to create a tube-like part by extruding two concentric cirlces, however, I would like to extrude them to a surface that, should it exist in real life would be considered as a single surface, but SolidWorks considers it as two. So when I try to extrude to surface, I do not get the result I am expecting (see image below). Any help is much apreciated, thanks!

SolidworksParts And Features