That is one of the correct addresses. Here’s also a PO Box one.
Write rescission letter that you wish to rescind per the 7 day rescission period. Be sure the rescission letter has your name (and your SO’s if he/she also bought), signature (and SO’s if he/she also bought), your address, contract number, today’s date, request for a refund, and no further charges. Might be also good to include a copy of the signature page.
Send USPS certified. Retain copies of whatever you send out. I attached the rescission instructions that Wyndham hid from you.
Don’t accept any calls from Wyndham. It will take at most 45 days to get your refund. Mind sharing how much you’d save with rescission?