He's doing his best
In fact, everyone is always doing their best under the circumstances. As my friend Al says, there's no such thing as irrational behavior. That's because in this moment, given the perceptions someone is holding, the way they behave is in fact the only way they can behave.
Consumers don't make choices as much as they react and respond to the inputs and assumptions they have about the marketplace, their life and your brand.
If you don't like the way someone is acting, understand you can't change his behavior, you can only change his circumstances.
This makes it really difficult to vilify the recalcitrant consumer. It's not that they're stupid, it's that you didn't explain it very well. As Zig has said, "I can understand why you're not interested. Other people who believed [insert belief here] weren't interested either. But once they discovered [insert new fact here] they were eager to try it."
Sure, people are willing to lie, break promises, willfully misunderstand, avoid responsibility and blame others. But why? They're doing it because under the circumstances, it seems like the right thing to do. As marketers, we can often change the circumstances.
There's an infamous scene in the Godfather where a movie producer turns down a 'reasonable' request from the Don. The Godfather is stunned. How could someone turn him down?
After the family kills the producer's prize racehorse (and puts it in his bed), the producer changes his mind.
What changed? Before the intervention, the producer didn't understand, didn't believe, didn't fear the Godfather. So he made what he believed was the best possible decision. Afterward, his worldview was forcibly changed and he made a different decision based on different facts.
Probably not a good idea to run around beheading horses, but it's a useful lesson in changing perception.