Look stylish but in practice misleading

In the shop they had a broad range of choice. From classical, through cowbow like to specials. Quality looked good: leather inside, leather outside, solid heel. Initially I was happy with my shoes. I was wearing them everyday. First days were uncomfortable as always and then leather stretched a bit. However I noticed that during the day and even next mornings I had a pain in my knees. Once I switched back to my normal shoes, it went back to normal. Once I weared Sasha Shoes - pain in my knees. Even though the heelpiece was stable, and quite thick I was still suffering. Company refused to take back as they were worn. So I ended up with shoes that I can't wear due to this, and money down the drain...