You have a tech that can't figure out whether your hardware is defective or his instructions are wrong, and is unwilling to admit it, and is providing a bandaid solution.
It seems that as a general rule today, phone support won't admit to not being able to find an answer, and will instead look for an answer, any answer, that will alleviate the most obvious part of the problem, and get you off the phone. (they're not in the business of finding a good answer, they're in the business of finding an answer)
I'm fairly certain I would fail at the task of finding any router for sale today that did not support a static WAN address. There may be a misconfiguration in your modem that your previous router accidentally handled as desired, that needs to be corrected.
That being said, not all useless phone support is entirely useless. Many times in the past I've called into my isp or applecare etc and spent time discussing the problem, and simply having a sounding board and a person asking questions and suggesting ideas sometimes stimulates my own thought process enough to consider possibilities I hadn't thought of. So even if they don't provide the solution, they often help me find it myself, and we both learn something new. Or sometimes I finally conclude that I'm just SOL and there's no satisfactory fix available. Now that's not a desirable answer, but it is an answer, and an answer is what I needed.
