When can I cancel my Rune Mastery subscription(s)?

You can cancel your subscription at any time during the subscription period and you will retain full access to your subscription functionality to the end of the subscription period.
The subscription however will not be renewed at the end of the subscription period.

Example:
Subscription start date: 1/1/2016
Subscription period: 1 month
Subscription renewal date: 2/1/2016
You cancel your subscription on: 1/17/2016.

Result:
You will have full access to the functionality until: 2/1/2016, but your subscription will not be renewed at 2/1/2016.
From 2/1/2016 you will have no access to the subscription functionality until you subscribe again.