You can easily find your billing history by going to Settings> Billing
https://dashboard.arena.im/billing
You will see:
Your Current Plan
Invoice History
Payment Preferences
Your Month-to-Month Pageviews
On this page, you will also be able to modify your subscription if you want it.
Ps. This tab is displayed only for the owners of the accounts. In case you can not see it, please reach out to the owner of your account.
Arena Team.