EVERYONE without Seguro coverage goes to the cajero with a cop. And I am a Mexican citizen. With pasaporte Mexicano IFE voting card, tarjeta socio ejidal de Chucutitan. I am also a member of IMSS in Micoacan with my coverage in hibernation because IMSS does not allow extended stays out of the member coverage area. I'll get to re-initiate coverage without obligatory coverage exclusion when I return.
If you do not satisfy your hospital bill in full you do not leave the hospital. You go to the police station. You need to ask your local hospital about this. Yes it is rude. But yes it is fact.