@Anonymous User
Welcome to the forum. Usually second accounts are the reason for double charges, if you're sure you've checked any other accounts you have (and any accounts other family members might have that use the same payment card) then try popping onto live chat, explain what's happened and see if they can track down what's happening.
To get to live chat, go to the following help page and choose the live chat option.
https://help.nowtv.com/contact-us/how-do-i-cancel-now-tv
