Agreed. If unhappy, politely make up a excuse to have to quickly leave.
Pay up full price then smile, nod, wai (again politely) and depart.
The OP should remember, this is her income, she needs to survive in a very competitive market, just think, some bar girls etc might not be brilliant after a contract is sealed.
Look elsewhere next time. As another poster said, their are millions of options.
Good Luck????.