My DS & DD bought crocs at the croc store in Orlando back in March, they have only worn them a handful of times and the stopper that holds on the strap has popped off! Can you order these on line...?
I had the same problem and I just went into the croc website and found a contact me place and emailed them. They sent me one free of charge. Or If you have a croc shop nearby I'm sure they will have some in stock