Poor customer service

I ordered medicine for my son which was prescribed by my pediatrician. When they called saying that it was ready for collection I asked the price because my medical aid is exhausted and I wanted to ask a colleague for the money so long since I forgot my card at home. They told me it was R79,90 so I went straight there instead of getting my card first as it was on my way from work. The assistant got the medicine but then when she took it to the pharmacist to check he comes and walks past with the page I signed and I overhear him saying this price is wrong and going on over the price that's not right. After several minutes the assistant comes back and tells me that he's just sorting the price out so I asked what's wrong and she says it's not right. Then he comes to the booth next to the one I was standing and he's just like the price isn't right I can't give it to you for this price. I explain to him my frustration and he says ya he knows he's sorrg but he can't help it and continues typing away on the computer. I just told the assistant I'm leaving. When I got back no one bothers to apologise not even the one who booked it out for me. It's really not on to treat customers like that over your mistakes!