It may be the padding and flooring beneath that's trapping odors. If so, surface cleaning will never remove it. Try shopping Craig's List, local want ads and calling carpet stores for a very large remnant. Carpet stores always have something they're dying to get rid of, cheap. You don't have to buy anything expensive. You may have to settle for a color or loom you're not crazy about, but it's better than living in a stinky house. For what you paid for cleaning products & two professional cleanings you probably could have bought carpet. Cut your losses and start putting a few bucks away each week for a large remnant roll, if at all possible.