Consulates usually follow a certain procedure when visas are refused. However,
Consular Officers should not refuse visa applicants on substantive grounds without first giving the applicant an opportunity to be interviewed in person
When refusing a visa application, consular officers should inform the applicant of the section of the law under which the visa was refused, as well as the underlying factual basis for the refusal, unless the facts are classified
When the refusal is based on substantive grounds (i.e., other than 221(g), the explanation should be provided in writing.
I believe, you should seek a review of the rejection. Make your Congressman aware of this memo and follow up with him. Unfortunately, there is very little one can do to appeal Consular decisions. Gentle persuasion through Congressmen, Senators and the Department of State does help.