@Anonymous User
Welcome to the forum. Usually this happens when people have more than one account with an active pass on each.
Might be worth checking any other accounts you have and if there is an active pass on any of those make sure you cancel it.
If that's not the case or your not sure where the other payment is coming from pop onto live chat, explain what's happening and see if they can help.
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
