you are in the correct place that is where you should see the unsubscribe button. Below is from the FAQ page. See last point if you purchased via Apple iTunes Store or Google Play Store
How can I cancel my subscription?
* You can cancel your monthly subscription immediately at any time and without any reasons.
* If you want to cancel the subscription for the following month, you must cancel at least one day before your subscription automatically renews.
* The cancellation process is located on your profile page.
**** In-App purchases via Apple iTunes Store or Google Play Store have to be cancelled directly in the relevant store.
If that is not the answer I can only suggest contacting tech support using this link
https://plus.wrc.com/en/support/contact/