I think that since you signed the original contract 10 days ago, you're playing with fire. And with your typos, it was kind of hard to decipher, but if I understand that you've mailed a rescission letter correctly, I guess that you've done all you can do. As to the new paperwork, I think I'd write a letter clarifying that a rescission has already been sent (include a copy) and hope that they add 2+2 and send you a refund. With Wastegate, if there is ever a benefit-of-the-doubt, they will take it.
We wish you well. Good Luck.
Jim