This is most likely because it is sold out. Use the Contact Us page to directly send us your enquiry. Also remember to sign up to our newsletter which will update you first about new release dates, discounts and events.
Simply click on book now button again, for the event you wish to book and in your checkout trolley the number for this event will increase.
I will always endeavour to try and fit everyone in otherwise, you may be put on a waiting list or online tutoring offered. Get in touch and we can discuss available options.