Unacceptable !!!!!!!

This is now the last time Im willing to try and book a ushaka snorkel for friends that are visiting.. the first time I tried to book we wore sent away because I never maybe a booking but before arrival I phoned in and asked if we would need to make booking and was told no we dont need to book. So we lost out and never snorkeled now that Im trying to book again knowing if I dont book we will not get to snorkel AGAIN , Im unable to make a booking ( Ive phoned in four times today.). Ive asked to speak to three different people and cant get through to them, I asked to speak to a manager and was told I will be phoned back but nothing .. This is unacceptable ... I will be waiting for a response...