Extremely poor service

We experienced extremely poor service from La Vita Spa Mycanos. We booked 2 treatments for two people, when we arrived a lady advised that they had staff issues (over the festive season) and they provided us with a voucher and advised that they had space for us within the next 2 days, which we accepted. After arrival the second time, the same lady advised that they only had space for one person and can accommodate a different treatment than initially booked. She again advised they had staff issues (over the festive season) - why could we not be advised of this in advance? I will definitely not recommend this spa.