Removing heavy rust from chrome wheels

I just bought some used chrome wheels, and there are several rust spots in the corners of the wheel. I used Turtle Wax chrome polish http://ec3.images-amazon.com/images/P/B0009JKGJC.01._SCMZZZZZZZ_.jpg and it removed a fair amount of surface rust, but there are still some spots where the rust is heavy and it will not buff out. What can I do to remove this? I will get pics when I get a chance.

If the coating is pitted and scratched (thats usually why they rust) then you cant do anything except get them rechromed.