The lady at reception had not heard of Wahanda and refused to let my mother leave the prepaid appointment I had made for her as a treat. Four or five phone calls later (two of which I was hung up from and once when I was asked 'is this conversation over yet?') My dad was made to print a screen shot I messaged him of the appointment confirmation and drive to show it to the staff. I was then asked for a sixteen digit confirmation code to prove I had paid which did not exist. Eventually the situation was resolved albeit with no apology. The lady explained that the Ruislip branch do not usually accept appointments made online (she also mentioned something about this being especially true on a Saturday?!) and this was why she had been confused and refused to accept I had already paid. I will not being going back due to the rudeness of the lady I spoke to and lack of apology when it was clearly their fault for not understanding Wahanda and confusing it with some long of Groupon/Wowcher site.
My mother advised the treatment was wonderful but hampered by the stress of being detained afterwards. If you decide to book here, I would not recommended paying before hand.