incorrect quantity given

Had a prescription given to me for 12 satchets inside a box and this box costs R740. Unfortunately I realized after 12 days when I wanted to use the cream that I was only given 6 satchets. I went there the morning of the evening that i was supposed to use the cream because of the pain of R740. I was told that we don't open watchers its too late for u to come and say that, besides our stock balances. I can't accept 6 satchets when this medication is so expensive. Please help. I don't know if the consumer council can help me.