Unfortunately, abuses of this type at various US consulates are not exactly unknown, especially in "developing" countries. If you can show that you are not in fact subject to the 10 year bar AND that you were never in the US illegally (which may be an entirely separate issue) you could try applying for the visa again at a US consular office in Canada and explain why the previous denial was mistaken. You would still have to convince the US visa officer of your intention to return to your residence abroad.
Otherwise, your visa might be denied anyway, even if you can overcome the issue of the 10 year bar. I would strongly suggest that you be represented by a competent immigration lawyer if and when you make this application. If the visa is still wrongfully denied because of the 10 year bar issue, the State Department Visa Office in Washington should be able to help. If, however, the visa is denied because the visa officer does not think that you intend to return to your residence abroad, you should not expect any help from Washington.
The above is general information only, not legal advice. It does not create an attorney-client relationship.
Roger Algase
Attorney at Law
algaselex@gmail.com