What should you do when the memory care facility psychiatrist would only talk to one family member?

Our mom is at a memory care facility. This facility has a psychiatrist that comes in once a month. When my sister and I wanted to meet with him about our moms concerns with her memory and her sundowning, he stated he would speak to only one family member. I had questions about some of the medications that were going to be given to her and he very rudely answered " like he had told my sister he will only speak to one family member ". I still work and my sister is retired so she had gotten there a few minutes before I got there he had answered some of the questions for her already, so when I started to ask the medication questions, that's when he said he would only speak to one family member and if I had any questions for me to ask my sister. Do you all think I have the right to go to the facility and ask for the psychiatrists office number so I can speak to him and ask questions about my mom's medications . I have concerns because he wants to change the medications that she is being given right now. Her neurologist had recommended these medications and I feel that he should be the one to change the meds.