Mine has a camera logo in the upper left corner that I can click on to change the pic.
In your profile options you should be able to select a URL for your page; that's how it works for personal pages. I cannot remember how to get there, and Facebook changes their interface every week so it is probably different by now anyway.
Fourth, constructive advice about what to do next would be greatly appreciated.
If my vote counts, I dislike the idea of white or black bars. If possible, I think it would look much better to simply rework the logo to fit the space. It can still be recognizably the same without being identical.