From Gary Lang's web site:
Dealer Info:
"We provide the highest level of customer service through our knowledgeable and helpful sales, service and parts personnel. We offer a top-notch customer experience. Whether you are looking for a new vehicle, online specials, need parts or service, "
Parts and Service:
"Our factory-trained service technicians have the experience and knowledge to ensure that the right service is performed on your Subaru. "
Perhaps you should explain to them that you had a less than "top notch customer experience," and, if their technicians were as well trained as they should be that they could tell the need between a valve and a solenoid.
Try writing a kind letter to the owner, explaining the circumstances and that you could realize how a "mistake" could have been made, but, you REALLY need your car fixed properly. Throw yourself on their mercy (if they have any) and show them a spirit of cooperation and possible compromise.