How to get the invoice of my last payment for skype number?

Hello,

I want to port my Skype number (US) to a different service provider. I need the latest invoice of the payment I made for the Skype number and some other details regarding the number. For example, is the number still active, or is it scheduled for cancellation? I have this number associated with a bank account in the US, and I live in Czechia. So I need to keep this number.

Any urgent help is much appreciated. Thank you.