I paid twice. How can I cancel one of them ?

You can check if there are two orders on your order interface. Please email to support@h2ofloss.com at the first time. The order can be cancelled before it is shipped. 

If your order has already been dispatched and is currently in transit. Therefore, we regret to inform you that we are unable to cancel the order or stopping the shipping address. I hope you can understand. When the package arrives at your address, you can choose to return one of them.