I could maybe see an argument for this if it wasn't a prescription. Like you have X disease, the pharmacist says Y medicine will hurt you and he won't let you hurt yourself. I would still be against that, but I might see an argument for the pharmacist thinking that you don't know enough about medicine to determine for yourself what you should take. But this isn't an uneducated decision you made because you googled your symptoms on webmd. This was a doctor telling you that the medicine was safe for you and determined that the benefits outweigh the risks. Some med school flunkie doesn't get to overrule your doctor's decision.

I want to say sue, but whatever you get from winning might not be worth it. You spend a butt load of time and money just for the judge to say they have to fill your prescription? Wouldn't be worth it.

I'd see if you can get a free consultation by a lawyer. It might turn out that violating HIPPA like this would be a big payout. And if the lawyer thinks it is a slam dunk, he might represent you for free just taking a percentage of the winnings. If you can get a free consultation it wouldn't hurt to just ask a lawyer and maybe you would get some cash.