@Cherie-and-Bill0
Sorry this happened to you. It sounds that you were more than helpful to these guests given the circumstance, but some people are so entitled, the only thing that would have made them happy is for you to disregard your own rules, let them complete the whole stay with the extra guest and not said a word about it. However, that's unacceptable. We have a right to set boundaries for our own listings.
I see that you offer self check in, which I am guessing is why you allow check in until 2am, but this seems very late to me. If you have guests arriving very late at night and there is some sort of problem, you are kind of stuck with them, for the reasons you describe. My check in is until 9pm and, if guests want to arrive after that, they need to ask me first and pay a late check in fee.
I think that I would not have been as generous as you. I don't know about the options in your area, but the fact that these ladies did not have a car is of no matter. They could have ordered another Uber to take them elsewhere and, I assume, checked themselves into a hotel.
I would have been furious if guests brought an extra person to my listing unannounced and the cherry on the cake is their comment "we do this all the time". No way, no how would they have stayed in my listing. If they are so disrespectful and entitled from the outset, there is no guarantee that they are not going to turn out to be nightmare guests. It sounds like, from the review you left the young lady, that they were well behaved for the remainder of their short stay, but the bad behaviour continued in the form of a 1 star review. Of course, not allowing them to stay the first night and not offering additional refunds (really don't know why you felt you need to do this) would have also resulted in that 1 star review, but trying to help disrespectful people like this doesn't pay off, as you have seen.
Going forward, I know it should be obvious as it's the maximum number of guests is stated in your description, but add it to your house rules as well and use stronger language. Mine not only state that the room is for a maximum of two people but also that only guests registered on the booking will be allowed to stay. All of my guests must confirm that they have read and agree to the house rules and there is an Easter egg question they must answer so that I know they have read the full version. You are then completely within your rights to say, "I am sorry but no. You agreed to follow my house rules and are already trying to break them. You confirmed that you had read them so you knew full well you could not bring an extra person."
I would then call Airbnb, explain that the guests have arrived with an additional, unregistered person without informing you and that brings their party over your maximum capacity. Ask Airbnb to cancel the booking and then they can contact the guests and try to help them find alternative accommodation if they like, but once the booking is cancelled, the guests need to leave your property. They are not your problem anymore. It sounds harsh, but it's a problem of the guest's making, not yours.