I have purchased several Sanuk brand sandals in the past.  I usually am very happy with them.  I ordered the Women's Ibiza Monaco Flip Flops from Amazon about 6 weeks ago, and two studs are already gone.  Unfortunately, the Amazon purchase return date has passed, so I am stuck with them.  I did go out and buy another pair at a local store;  this new pair fits very well, and has all parts intact.