Naturalizer Women's Banks Slingback Pumps Black Leather 8.5M

These are GREAT shoes! Bought my first pair over 5 years ago. Bought this pair to replace my first pair that's STILL in pretty good condition (except for the wear and tear on the tip of the top and a scuff I made on one heel - which I covered up with black shoe polish, but figured it was time for a new black pair). Wish the black came in patent leather (have the gunmetal in patent leather)).

I LOVE how these shoes look, but I had a problem with the sling back straps on my heel. Even though I put the buckle at the lowest position they were still too loose. They actually FLOP on my heel and fall off. So disappointing! I hope I can find some sort of adhesive to solve the problem.