Lied to by a doctor?!

I reluctantly agreed to have a colonoscopy provided they take biopsies. My PA assured me that she had order biopsies to be taken. I even asked the doctor preforming the test if they were taking biopsies and again was reassured that yes they would be taking biopsies. When I came to and I questioned the doctor again she said no they had not taken any biopsies. How am I supposed to trust these people when they lie to me?