Hospital Bill from 2016 not paid. Why???

I received a statement directly from Netcare Clinton Hospital in Alberton, stating that i need to pay a bill of R115 000, in which my son was hospitalized for a week there. They are threatening to take me to court over this in which i do not understand why as it was a hospitalization case. My son was non-responsive and was taken by helicopter to that hospital. Please can you look into this? I will attach the statement, this is over a year ago now.