Got told in an email I needed a centrelink health care card for subsidized fee.

I applied for a course that was in the Cert 3 guarantee courses in January. I got a phone call a few weeks ago saying that I'm eligible for the subsidised fee which I accepted, however, I got an email today saying that I need to hold a centrelink health care card to be eligible for the concession/subsidised fee. I never read anything about needing it for Cert 3 guarantee. I wondering if this is an error or something. I doubled checked the website and it said that you need a centrelink healthcare card for concession but nowhere did it say it was needed for subsidised fee.