Unfortunately yes. Most nurseries charge a flat monthly fee regardless of closure dates/bank holidays etc.
If you are away, it is your choice to not take your child there, the nursery cannot be expected to fill your childs place for just 1 or 2 weeks, so I am willing to pay for this.
It's the over Xmas payment and paying for bank holidays which has always annoyed me, afterall they have no intention of providing the service on these days so why should I pay for it. When I was self employed, if I did not work I was not paid, it should be the same for all service providers.
I have come across the same situation with childminders. Not all childminders charge (before anyone takes offence) but I have not come across any who do not charge where I live.