This is what we found:
To cancel your account, call the College Board Customer Service at 212-713-8000, Monday through Friday, 8:00 am to 9:00 pm EST.
You’ll get some verification questions, so make sure you have your registration details ready.
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.