Continuing on-topic...
Kohta, in addition to providing a bad Reseller Ratings review and filing a complaint with the Better Business Bureau, you may also consider filing a formal complaint for fraud with the US Department of Commerce. Once the bank lawyers get through with them, they'll have to deal with a DOC indictment. If that doesn't wake them up, nothing will.
Continuing off-topic...
I find the idea of insisting on American English idiom and accent during transactions a bit more than bizarre. For much of the rest of the world, it's multicultural and multilingual. Although English remains the lingua franca, making a sincere effort at understanding one another, regardless of English proficiency, is simply a part of everyday life. Getting upset, or being derisive of another person's speech marks you as mean-spirited or odd at best.
That said, the only thing I find more bizarre than Americans who are intolerant of those for whom English is a second language are Americans who don't bother to take the time to improve their command of their native tongue.