Pannier-bag complaint

So I have this pannier-bag by Arkel, which is all stylish and doubles quite well as a shoulder bag. However, this being the first time I’ve actually used it on my bike, I learned somthing. It sucks dead donkey dicks as a bike-bag. I think it is too wide, so that with every rotation, my heel smacks against it, unless I pedal at an awkward and unnatural angle that is really inefficient. I’ll see if I can do something different somehow on the ride home, but if not, I’ll have to junk and buy a bungee cord to strap my knapsack onto the rack.