There's a sign at my pharmacy that says that prescription consultations cannot be given out while someone is on the phone due to privacy reasons. I suspect that this is the case here, even if it was a refill. Because they may still have to ask if she needs a consult/info on the medicine and she may still "yes" in which case they can't do anything while she is on the phone.
Further she is being WAITED ON by other human beings who deserve her entire, undivided, attention. Pharmacist side.
Maybe the pharmacist could've handled it better, maybe say they can't give it out without the consult or with her being on the phone. But, damn, lady. Get of your phone for two damn minutes to talk to another human being who is serving you.