As far as I know from girls from cowboy,nana and patpong, they dun work 365 days a year. They sometimes go other countries for work when the time is ripe ( Immigration issues ) and go back hometown to rest for a few weeks or a month. None of them will pay hefy month long barfines for their absence from the bar. They just need to tell the bar/Mamasan probably a week in advance for more lenient management
For the case I mentioned 20k baht barfine as and when he comes to town. Everyone benefits from the scenario. The customer need not pay hefty barfine each time he comes to Bangkok which is quite often. The coyote need not work everyday as I know her personally she only wants to come to work as and when she likes. Lastly the Mamasan is more than happy to accept a bonus of 20k into her pocket and placed her as sideline/part time. Win-win situation for every party. Lol.
So the point is if the girl really ask the customer to pay a month long barfine, she is really taking the customer a fool. No offense. By the way, probably it's your girl but not your friend'a girl.
Baccara have part time girls where they come work as and when they please and they pay a fee to the bar for coming to work each day and they are not paid salary at all end of month. They just "used" the establishment to get customers to go ST and LT.