Derma Clinic - Thailand

I've been going to this clinic for a few years now, have kept up with the miso therapy needles, problem is, last time I was there I noticed that one of the needles I paid for wasn't there at the end of the session. I forgot about it until today, when seeing only four empty needle dispensers at the end of the session, and I asked them where the 5th needle was, the Doctor Punchuk ( or Dr. Gift), had left the room and called out she can't find it, and came in pretending to look in the bin, leaving the room again. The receptionist smiled very cutely at me and said 'ok ok'? ( which was strange because she's not a smiley type"
Now that I'm back in my room , I realize I've been taken by the oldest trick in the book. I'm a trusting person and coming from Australia where they would never put something like that over you. I know its too late now but next time I will not only let them show me the five bottles before the session, but ask them to show each time they refill the needle as well.