Customer Service

So, I have a question.  When you call a company (i.e. a pharmacy) and asked for their services, wouldn't you think having your information available and being polite would be something you would automatically do?  Why is it that every stinking customer that calls into my work has a chip on their shoulder, and thinks we OWE them something?  I just had someone rip my head off because I asked for a prescription number for the medication they want filled.  I am a pharmacy tech, not a mind reader!