If you're unsatisfied with your Meural Membership, you can cancel at any time by visiting https://my.meural.com. Click the User icon in the upper-right corner, then select Account Settings. From there, scroll down to Membership and select the 'Edit' (pencil) icon to cancel.
Your Meural Membership will continue through the last paid month or year, depending on whether you originally purchased a monthly or annual Membership.