Adding to what @redchiz1 has said, the only UK free trial is for Hayu. Is that what you had a trial of?
Otherwise, you didn’t have a free trial, you took out an immediate subscription, and were charged accordingly.
Though not by the £1, which is temporarily reserved on your card, not charged, so it only alters your credit limit, not your balance, and that only for a short period.
And Apple is a red herring here; I don’t know why you mentioned them; even if you signed up on an Apple device, you didn’t sign up through Apple.
When you cancelled, did you get an email confirming this? If you didn’t, then you didn’t complete the cancel correctly, and you should go back and redo it.
But whether you did or not, you signed up for at least a month of Now membership, and the deal is that when you cancel during that month, there is no refund, but you can still use Now for the month you have paid for.
But if you want your quids back because the ‘free trial’ offer has backfired on you, then gather the details of what should have been your free trial and contact Now for a refund:-
The following link, which leads you to direct contact with Now, is for when the Community can’t help, and the Help can’t help:-
Avoid ‘Get Help Quicker’ there; you won’t.