I am a little confused about how the pandora and chamilia beads/bracelets are interchangeable. I have a pandora bracelet. When I was at disney world last week I purchased a glass mickey chamilia charm at the World of Disney because I read that they were interchangeable. When I place it on my pandora bracelet, it just slides on it does not twist like my Pandora charms. It does not seem like the charm has the grooves like my pandora charms. Are the Chamilia charms larger than the Pandora charms or did I get a defective charm???