Blue Cross Blue Shield of Illinois

My husband was told that BCBSIL would pay for 2 shots once a month when we called to precertify. He had been getting these shots with our previous health care coverage. After precertification over the phone we received a letter dening coverage. To me this sounds like discrimination which is against the law. The way they are getting around this is by saying it is not medically nessasary. How would they know when they have never treated my husband only his doctor.