If you canceled your membership to the OONYX Patreon before the payment cycle begins (the 1st of the month) and were still charged, it is likely your payment initially declined.
When the 1st of the month rolls around, Patreon begins to process all payments. If your payment does not process on the 1st, they will continually attempt to bill you.
If you update your payment method or get enough funds in your Patreon account to cover the charge, you’ll be billed.
For example: Patreon bills you on March 1st for your membership and it declines. You cancel your membership on March 2nd. Patreon continually attempts to bill you for this past declined bill. You later have enough funds in your account on March 5th to cover the payment- When Patreon runs your card on the 5th, it processes.
You’ll be able to see if you have any past declined payments in your Patreon billing history.