Black Pointed-Toe Ruched Slingback Ballet Flats

I’d been searching for a pair of flat, long pointed toe shoes forever and was delighted to find these. Unfortunately, the fit was a bit tight (I have narrow feet), but worse, the slingback buckle is so tight that I could barely undo the strap to put the shoes on, and when I finally got it free, it was impossible to slide back in. From the photo it looks as though the strap might be elastic; however, the ruching is merely aesthetic. Otherwise the shoes are quite beautiful and exactly what I wanted design-wise. Also note that these are synthetic not leather.