Pontins Questions !!!?

Me (17)(female) Friend (16)(female) and my brother (18) are booked up to go pontins in a week.. any way my mum rang up to jus confirm it and the silly woman on the other end of the fone said, they will need some one over the age of 25 with them. Is this tru, they said nuffin about this when we booked it online and we put in all the ages, and they sent us a letter confirming everyones ages, me brother 18 is acting as the adult surely thats good enuf? its not a full group of boys or a full group of girls cause i know they normally get funny about tht.