I had the same problem. I hid the demo banner as stated above then I:
1. Opened Appearance >>Widgets and selected the Banner Widget Wide.
2. Added a Text widget to the Banner Widget Wide, placed the html for the image path to my uploaded banner, e.g. <img src=”http://www.yourdomain.com/wp-content/uploads/2014/04/image.jpg”/>
3. Save and close.
I did see that statement about non-support when I did a search for Swatch. So I guess those several forum respondents were just helping out of the goodness of their hearts, but under no obligation to provide support. Ok, thanks anyway.
Oh, I saw several other Swatch related posts with extensive comments when I did a search. Granted, they were older. Has the policy recently changed? Thanks.