Run very big, spotty markings in visible places

I had to return the mules, not very happy with the purchase, they do not run true to the size, not even near, they seem 1.5 size bigger than my regular UK8 (41) size. Sadly, I found some strange marks, in upper part of the right shoe. I like the way they look but as they are not very stable I nearly damaged my ankle when taking just a few steps in my bedroom while trying them on, strangely they are very wobbly, rounded soles are too rounded adding to the lack of stability, too floppy, the design makes them hard to wear. Not for me.