Failure to let me know of the costs

I got sick at work and informed my superiors and they called the ambulance from medi response. I was transported from Melrose to Edenvale. The reason for Edenvale is because I didn't have medical aid to cover private hospital. What I didn't know is that later on I was gonna be sent a message on Whatsapp of the money I owe to them which was around R4000. Now what I don't understand is that why was I not told that I would need to pay for the ambulance service.