@Anonymous User
There are a couple of things, another account could have been created using the same payment details.
You can confirm using this link.
https://help.nowtv.com/account-finder/
If there is only the 1 account, you can check to see recent payments by
https://help.nowtv.com/article/how-do-i-view-my-payment-history
You can also try filling this form out, but its not a guarantee.
https://account.nowtv.com/payments/query/incorrect-charge
FYI that I do not work for NOW, just a NOW customer trying to help