Texaco 7 Day Tire & Brake

I came in with a smog repair and they ended up installing the wrong catalytic! They over charged for the part and laver I come to find out later. Wen I go back they weren't willing to help out, replace, discount, or apologize. Now I'm stuck having to still replace the one that is bad! I don't have any help and it seems like the Revdex.com can't do anything about it also!