Advanced payment for one night bookings?

I have a one night booking a week away  and have just received an email, purporting to come from the site, asking me to ring with my member details & pay in advance by card as per the rules in the handbook and on the net or reoly with contact details and they would ring me back.

I am a little concerned it is genine because I have not had to do this before. Why would they want my membership number. I have searched through the sites rules & Clubs terms & conditions and no mention of this, in fact it says payment on arrival. I do not have my hanbook to hand to see if it says anything. There are some things in the wording of the text which are not correct.

I have replied with my concerns asking the warden to ring me using the number they already have.

Has anyine else aware of this new pre payment or such emails? 

Regards, Roy