The fear of making a phone call to authority figures may be related to a low self-esteem coupled to a metabolic disorder that produces too much adrenaline. The metabolic aspect needs to be treated BEFORE the psychological aspects.

Please read:

Treatment of a Low Self-Esteem

And then study the

Self-Help Psychotherapy Course

from beginning to the end. Concentrate on:

What is Transactional Analysis? (TA)

and

Assertiveness Training Program