I don't really see the religious issue here. I'm a non-Christian, so I don't really care all that much about the religious beliefs of the person who waits on me in a store.
If my doctor prescribes a medication for me, I expect that prescription to be filled when I go to the pharmacy. Right now, I use Walgreens, because it is convenient for me to do so. My wife does, too. Between us, we give our local Walgreen's a good bit of business.
One refusal by Walgreen's to fill a prescription for either of us would instantly result in our transferring our prescriptions to another pharmacy. It would also cost that Walgreen's the multiple prescriptions of my wife'd parents, who are in their 80s and take lots and lots of meds.
I am not interested in the religious beliefs of the pharmacist. They are irrelevant to me. They will either fill all of my prescriptions, or they will be filling none of them.
Would you feel the same way if one Walgreen's pharmacist were to tell you that, in order to have a prescription filled right away, you would have to go to another near-by Walgrren's?