Given wrong dosage from prescribed

I went to clicks pharmacy in wonderpark this afternoon were I was assisted by akani nkwinika. Firstly when he saw my prescription he asked what my medical aid was and I told him I was on banked. Then says to me b ankmed will not pay for this I had to ask him process thepurchase before concluding that b ankmed will not pay. The medication was paid in full with no levies. I could have turned back with the beliefe that my medical aid will not authorise. I was given my medication and it was 30mg capsules instead of 40mg capsules as prescribed by my doctor. When I asked him why he gave me the wrong dosage he said the dosage prescribed does not exist in the medication and insisted that I have used it before and he continued insisting that 40mg DOES NOT EXIST I went bag home and searched for my old pack of the medication which turned out to be 40g. I expect a pharmacy like clicks to have professional staff with understanding of the medication they are dealing with and is very worrying to come across a pharmacist whoz rude and clueless when it comes to medication. I am now stuck with medication I was not prescribed which is long paid for and open. I need proper dosage or money back