Some interpersonal communication skills are directly linked to your intrapersonal communication. Your relationships with others are influenced by your self-communication. Self-disclosure: Should you share information about yourself with someone else? How will that influence the relationship? Approval-seeking: Do you need someone else’s approval to be happy?Responding to criticism:  Do you need to change? How does criticism make you feel?Apologizing: Have you done something wrong? Making a good impression: Are you intentionally working at how others see you?These interpersonal skills all start with a positive self-concept

First of all, I would start off presenting yourself: Dear XYZ support team I am the web developer in charge of example.com website. By presenting you this way, you are establishing the frame to treat you, hinting that you should be presupposed to be somewhat proficient, so they could choose to answer in a more technical detail.

Hey, I'm a PhD in [field] and do [whatever] professionally. Before calling you, I've narrowed down the problem to [something on their end], so that's what needs to be addressed. If I could speak to an engineer about [specific problem], that'd be great; but if we've gotta walk through the script, let's just knock it out quickly. If they end up requiring the script, then the best way to use your expertise is to run through it quickly. Keep the chit-chat to a minimum and just do the stuff efficiently. If they start describing how to perform some step, you might interrupt them with, "Got it, just a sec.", then let them know once you're ready for the next step.