Does the email say that there is a free cinema pass in your account waiting to be redeemed if you wish, which nowtv sends out occasionally to random selective customers.
Or does the email say something like thanks for purchasing a cinema pass ?
Anybody else in the household that can either access your nowtv playback devices or your account who may have started the free trial and didn't cancel the cinema pass before the free trial ended ?
First thing that i would do is go to My Account > Passes & Vouchers on here and cancel the cinema pass.
When you cancel the pass make sure that you follow the step by step instructions until you see the green thumbs up cancelled message on screen (suggest taking a screen shot of the cancel message).
Then jump back to Passes & Vouchers to see if it shows cancelled next to the cinema pass.
You should also receive a notification email from nowtv within three hours of cancelling the pass.
As a further safety measure on your account add a payment pin by going to My Account > Settings & Pin's which will prevent other people who have access to your devices starting free trials or buying passes in the future.
Then jump over to live chat to see if they can help with the refund with regards to cinema pass charge on your account.
Link here to live chat.