It's IMPOSSIBLE to cancel the payment I just made. I accidentally paid it twice and they both posted to my account! One yesterday and one today.
While it's great to know that you had made a payment to your account, making an additional one by mistake is something we'd need to know about right away. While there are some scenarios that would not result in a refund of the additional payment, we're going to need to access your account to see how it was made and what our options are. Please check your Private Messages for more details.