What should I do if my RX medication was shorted to me at the Pharmacy?

I take Adderall for ADD. This is a controlled medication. This past friday I picked it up, brought it home, and when I opened the bottle it looked like the pills were not all there. So I counted. To my surprise, I was right, there were only 24 capsules, when there should have been 30. 6 pills were missing! Does that seem suspicious or could this just be a mistake by the pharmacist? I could see 1 or 2 being miscounted but not 6! How do I approach this situation? I want to tell the pharmacist, but do you think they would believe me, being that this medication is controlled? Would they give me the 6 that I'm owed? I paid for it! And its not cheap. I was thinking about just blowing it off and the next time I go to get it filled, I was going to tell the pharmacist that I was shorted last time and have him/her double count in front of me. What would you do?