You'll probably find that you won't be able to get your money back because it does state in the T&C's that you are responsible for cancelling the trial prior to the renewal date.
I have had a trial which I forgot to cancel so I tried to get a refund but sadly the company quite rightly said no.
So I cancelled it from the following month, then bit the bullet and just wrote it off as a life lesson and enjoyed the content for that month.
Not to be harsh but you would have received an email if not like what I should have done is put a note in my calendar.
Sorry I can't be any more help but this is a difficult situation to be in.
Even if you didn't get an email from NowTV, the law is very clear.
It is YOUR responsibility to ensure that you cancel any trials you sign up to else you'll be liable for any subsequent subscriptions that your card may be charged.
You could try asking your bank to claim back the money but the fact that you have admitted that you had forgotten to cancel the trial will mean that they will be able to claw the money back and if you make a false claim against your bank (i.e. You make a false statement to claw your money back) then this could technically leave you open to making a fraudulent claim for monies your not entitled to.
What's more NowTV could take you to the small claims court or pass it on to a debt recovery agency which will most likely cost you even more money as these costs are normally covered by the person with the debt.
My advice is simply forget it and chalk it up to experience as any action forward you take will be fraudulent and or cost you much more cash than the initial fee.
Just out of curiosity, what package did you forget to cancel?
You can try filling this form out, but as @iHubbi don’t be shocked if you don’t get anywhere