I Went To Refill My Script And Was Informed Yesterday

I went to refill my script and was informed yesterday the birth control pill called B-Yaz has a generic called Rajani. Until now the brand me cost $0.00 the pharmacies told me the B-Yaz will cost me $160. As of now the pharmacies don't have the Rajani on their shelves and it will be awhile before they do. My question is what other birth control pill out there is equivalent to the B-Yaz? Why doesn't the insurance company deny paying? I have no control when the generic will arrive at the pharmacies.