You are definitely not the first to be upset about the zestimate and its inaccuracy. Agents have to explain to clients that the values are inaccurate on a daily basis. The bigger Zillow gets the more people want to argue that the zestimate i accurate. It is frustrating for everyone involved.
For an accurate value please send us the address here and we will send you a free CMA for the homes value: http://www.lvrealestatehelp.com/selling-real-estate.html