It is unfortunate your Real Estate Agent did not understand the idea of "excellent customer service"... There is no excuse for not returning calls or failing to show up for scheduled meetings. These are good reasons never to use this Agent again. As far as not bringing any Buyers thru your home, your Agent may not be working with Buyers in the price range or target search criteria your home offers. Most often, he/she is relying on other Real Estate Professionals to bring in qualified buyers by extensively Marketing your home.
Regarding 'under-selling' your home, I would ask the question 'Did your Agent give you a market appraisal of your home? Did you interview other Real Estate Agents and did they give you a Market Evalutation? Your Real Estate Agent sets the price of your home based on Sold & Active comparable homes in your area to bring in Buyers (and ultimately an 'offer'). The Buyer and Seller ultimately come to an agreement on the final sales price. If I were a Seller in this challenging market and got my home sold, I would feel very fortunate. Remember, you can leverage the purchase price of your new home, to get back what you feel you left on the table at your former home.
Since the market is still declining, you could be selling your home for less today, than when you sold it.
It is unfortunate your Agent didn't give you better service and attention.
Best of luck,
David Jaffe-SRES, CDPE