If you purchased a membership that renews/has a billing cycle (like monthly, or yearly), you can view the next time your membership renews, which is also the next time you will be charged, through the memberships tab of your profile.
View the next time you will be billed for your your memberships by going to your Player Profile > Click on the Settings gear > Click on Memberships. From here, you will be able to view all of your memberships > Click on a membership> Under the Details tab you can view when you will next be billed. Under the Transactions tab, you can view all of your past transactions for that specific membership.
From your OpenSports Profile, click on the Memberships tab in order to view the memberships you have purchased > You will see your membership cards which will show when your membership renews (which is when you will be billed next).
Players, if you are looking for a guide on how to cancel your membership contract, read here.