I bought the wrong size binders at OfficeMax...?

I don't see why not. Just go back to office max and tell then that you took off the sticker and that you tried to fit your paper and dividers into the binder but they all didn't fit. Then show the worker your recite and ask them if you could exchange it. I beileve that they will let you exchange it. I mean, you didn't write all over it so I dont see why not.