As long as you sent your letter of rescission by certified mail so that you have
I didn’t know about the 15 day period. Thanks for letting me know.
proof that you mailed it, you should be fine. Did everyone who signed the purchase contract also sign the letter? Did you mail it to the address shown in your instructions? If you did all that, you're good. There's nothing else you need to send according to the instructions above.
I didn't have any problem reading the last three lines with a magnifying glass. I think you're fine. It might take up to 45 days for them to refund your payment if you paid by credit card. Just keep monitoring your card. They aren't under any obligation to get back to you, but they are under a legal obligation to refund the money you paid them. Wyndham is a reputable company and I think you'll get your money back.