As Gary said you have to be your own advocate in this process. The squeaky wheel gets the oil!!!
Theres no way you should have pain from the positioning of your head and neck for the treatments. TELL THEM right away so they can make the proper adjustments for you. There should be camaras and microphones in the room so you can let them know during treatment. My rad techs were great people. Im sure they also don't want you hurting from the positioning of your body.
You want to have confidence in your medical team to ease your mind. One thing I've learned is that all doctors are human just like you and I. They are not perfect. Not returning your calls is unacceptable. Let them know this.

My IMRT treatments only lasted 15 minutes.

Best Wishes, Danny Boy