Should we trust this Psychiatrist and nurse?

My daughter was out on Xanax for anxiety and he recently upped her dose to 2 mg a day and verbally told her to do this but it's written as take one .5 twice a day. He then said he'd write for whatever works for her. But--I called them to find out how she should be given these because I didn't know if I should give all at once or space then out. The nurse just called me but I didn't answer because SHE BLOCKED HER NUMBER. It showed as unknown. I figured it was a telemarketer. Well she left a message on how she should take this Xanax and I'm saving this voicemail forever because I find it fishy that she would block the number?! Am I being paranoid? I feel like they're trying to save their asses if she goes off the deep end and maybe blame me that I'm giving it to her wrong but Ive been following their instructions perfectly!!