The usual cause for the duplicate payment for your subscription that we have seen is coming from PayPal payment method.
PayPal will auto schedule the payment base on the active PayPal subscription you have created in your PayPal account and send the payment to our system.
To avoid any duplicate payment being made, logon to your PayPal account and revoke one of the subscription ID. If you need help to know which is the active PayPal subscription ID connects to your subscription in our store, feel free to reach out to our team.