They are unresponsive on emails and their phone line is often busy.  

The property needs a fair amount of work, but I was able to get it for 10% less than a similar neighboring property that sold one month prior.The listing agent has been very unresponsive so far, and today I found out that he has not properly notified the existing tenants of their TOPA rights.

My current accountant does have knowledge of real estate but has been unreliable and unresponsive many times.

They wouldn't even help me cancel a month-to-month lease with a public nuisance...I got on the phone with someone from maintenance yesterday to check in on the status of a request because whatever vendor they've farmed the work out to has become unresponsive.

Worse yet some landlords are unresponsive and technologically inept.

Our insurance adjuster is completely unresponsive to direct questions, and considers our residence habitable when it is not.

Doesn't hurt to shop around, but don't get so hung up on fees and rates - with complicated transactions you want to work with the best, not the cheapest, and you want to avoid losing years off your life due to the stress of dealing with an incompetent and/or unresponsive lender.

But in this case time was of the essence and you had an unresponsive owner, so what were you supposed to do? 

After dealing with unresponsive seller agents and my agent severing ties due to my interest in contacting the seller agents to expedite the process, I decided to pursue the DIY route.I work off realtor.com considering it has the most up-to-date listings off the MLS.

You have let her get away with being unresponsive for months, so she is probably thinking you are a push over.