phone calls

this is mostly for customer service or other situations involving strangers. i am usually not that comfortable on the phone with friends anyway (bad signals i guess?? idk. im afraid of misreading them but i always am). it is especially unnerving to call customer service and the like. even if i know they will probably just read a script? that's sort of scarier idk. does anyone have any tips about how they deal with phone related situations that can't be avoid? like interviews, rescheduling, etc. how do you prepare yourself? or do you just try to find other ways out and what are good alternatives?