The main thing to keep in mind is this...
It is similar in any hospital in Mexico...
The doctor comes around and discharges you. You get wheeled to the financial office in a wheelchair. A cop (civil protection) pushes the wheelchair.
You pay. Pesos, dollars or credit card. Or you do not get released.
At the end of the day when the financial office closes and you're still sitting there short of "funds" I will give you two guesses where you're going next. No, you cannot bolt for the door. Experiences with several million Mexicans has taught them well.
This is not intended to intimidate anyone. It is meant to educate.