This is happening to me too, I presume you saw the page that showed you the steps into cancelling your subscription but when you saw it, it had options unlike the pop-up I assume you're getting. I've been trying to figure this out myself and it seems the best bet is to call them. By the way Adobe customer support services are terrible.
This is an open forum, not Adobe support... You need Adobe support to cancel a subscription
-start here https://forums.adobe.com/thread/1703848
-or by telephone http://helpx.adobe.com/x-productkb/global/phone-support-orders.html
--and two links which may provide more details, if the above links don't help you