My stiletto's are a 1/2 size too big!?

They are about a 3 in heel, pointed toe stiletto, and they are just a bit too big for me - which makes them uncomfortable. I have tried the gel heel liners, but they don't work, and i have a ball-of-the-foot gel cushion as well, but my foot still slides forward...i also put some tissue in the toe to help, which did a little...but is there a specific product that i can use that will help with the shoe size?

brand name and where i can find it? thank you for your help!