How to choose featured ad image

I just posted an ad for a $5,000 telescope and paid for 'featured ad' placement.  What shows as the featured ad is an eyepiece; one random image from all the uploaded images.  The image should be the "first image" (the telescope) in the lineup, as stated on the webpage.  How can I fix this?  Thanks

Just reporting that this is still a problem.  If you look at all of the featured ads, they have the same problem -- the picture is not the main picture in the ad.  In my case, it is a handset for a mount, not the mount.  When I go to my ad, the mount is the main picture.  This is something worth correcting if anyone is reading this.