I would call BnB straight away. Explain that your guests broke your house rules (When you say you wrote I presume you mean in your house rules) that they were noisy till 6 a.m. in the morning, brought in a girl in violation of your rules, carried on being noisy after being asked to stop. Also explain your neighbours and other guests have complained.
Personally I wouldn't want to give them another chance this evening - you need to think of your other guests and neigbours.
You can say to BnB that you want the guests to leave and ask for their help to make this happen.
Any refund will depend on your cancellation policy. If they break your house rules, and you have a strict policy they shouldn't be able to get a refund.
Calll BnB now (number is on your booking confirmation)