Pharmacy at Clicks Gordon's Bay does not stick to their offer

I had a prescription for a cream and went to the pharmacy at Clicks Gordon's Bay. The price was R350 so I asked if she has an alternative product at a lower price and she offered me one for R250. So I discussed it with my wife and we decided for the cheaper option. Even before payment I saw that the price was now R300 and not 250 anymore. So I asked the pharmacist (Mishka) why she did not stick to the price of R250 anymore and was told that on this R250 she had to add dispensing fees etc. I rep**** to her that she can not change her price within not even a minute and add other fees as she likes. So I spoke to the manager of the pharmacy and explained it to him. I told him that he can not expect from a customer that we ask if there are any fees on top of prices which they display or offer me verbally. He completely understood and apologized. Unfortunately he was not willing to stick to the verbal offer of R250 and asked me what I want to do. I tried to explain to him that he should not ask me this kind of question and rather stick to his offer but I had no chance. So I obviously did not buy this item in his pharmacy and will in future also not buy there anymore. I had very friendly and professional help at another pharmacy and even got a much cheaper product on top of that not even for R50 and it also helped.