Make sure all your Passes are Cancelled, which you can do for yourself.
Beyond that, getting them to forget you altogether is rather difficult.
But now the myth that NowTV spontaneously restart subscriptions has been laid to rest, you should have nothing to worry about there.
Never leave any personal details on a customer forum, it is a breach of GDPR rules.
Like I just mentioned it's a customer forum and Now TV staff from time to time monitor it. Your best and quickest option is to send an email to customer services and Now TV will get in touch with you.
As I am a customer I cannot be much more help than that. You will see the email address in the below picture