Charge in my apple I'd for something?

I tried downloading a film and haven't hot enough space on my iphone, so I left it and just got my apple bill through saying I have been charged.
What do I do now as I can't download the film so won't be using it?

Added (1). Elizabeth c-I don't have a computer my iphone it basically my laptop and computer

Watch it on the computer

0844 209 0611 call this number, they will help you out, they won't put the phone down until they sort your problem out, it's apples helpline number btw.

Mine did this once, but not because of the lack of space, but because of a bug.
I simply phoned Apple and explained, and they were happy to give me a refund

Try doing that tomorrow, it might just help.

^ Like this person above me said.was a tad faster than me.