Humana and stereotactic devices

I just recently found out that Humana is denying CPT® 61781 and 61782, they are not going to pay for this code at all. They stated they sent out notification back in October of 2013. We do have a contract with them, but I am wondering how can they deny a CPT® code forever and is it legal? Anyone having these issues with Humana and/or other carriers?