There was a JAV star in Feb who ended her trip early because of too many customers and being in physical pain from it.
There are a surprising number of girls at this shop who feel pressured to work while sick (no, do not DM me on this as I'm not going to give further detail).
Banging 12 people a day is not physically normal for almost anybody and you will be hard pressed to find shops that will book girls that much - whether they are a flushing house, a soapland in Tokyo, or a hotel girl in HK.
These complaints surface again and again with this shop because there is obviously a systemic issue with their scheduling. No need to apologize for them, they are making plenty of dough