Yeah, look, that sucks, but it's not exactly hard for a shop to manage in this day & age. Just buy a phone with caller ID, record the number as a contact for the booking and have a one-chance policy ..... if you don't turn up and don't call to cancel, your number gets blocked from making another booking in advance. Easy.
Weeds out the time-wasters and unreliable punters, or worse, shitty competitors making false bookings. And the cost of the new phone is probably covered by just ONE hour booking that avoids an otherwise no-show.
Who knows?? Reliable punters might even end up having future bookings honoured, and the girls will end up actually busy instead of wasting hours in the shop not earning (though I believe that's not a concern at 533, they're busy enough anyways). Win win, just a tiny effort needed from mamasan / reception.