When you arrive at the premises of the escort, you are greeted by a guy. Alternatively, a man waits outside the address for you. He leads you to the door.
The guy will then ask you for the payment.
Once you hand over the payment, you are told, in no uncertain terms, to leave.
This can be a dangerous scam. We would advise you to leave as quickly as possible and if you can report this to Crime Stoppers then do just that.
If you choose to confront the guy then be very careful as he has prepared himself for this encounter whereas you are more vulnerable as you have been surprised. Walk away. Report it if you can.