What ought one to expect from a luxury travel agent?

The primo issue for me is access and prompt response. I currently am working with an agency that goes off line often including weekends and it's not working well. In fact, I am amazed I have strung myself along thus far. I may well be an idiot.

I am accustomed to paying quid pro quo but am uncertain how this works with TAs. I would be fine to pay beaucoup extra for true luxe service. But I don't know how to wrangle this. What I want and am willing to,pay for is access as I need it. Which means the agent needs to be available ... is this unreasonable?

What say you?