Incorrect booking made

I purchased tickets online on the 15 June 2015. I paid for the tickets with my credit card. I only realised after I had completed paying that I had booked for the incorrect day. I mistakenly booked for Thursday 18th June 2015. I phoned TicketLine on ***and the consultant asked me if I had printed the tickets. I said yes, I had printed the tickets. The consultant then advised that since I have printed the tickets then she cannot give me a refund. I know it was my mistake for choosing the wrong day. But I did not see any warning message on the Ster kinekor website stating that if I print the tickets then i cannot get a refund so how was I supposed to know this? I am trying to cancel these tickets 3 days before the show date, how is it possible that Ster Kinekor cannot refund me ? I must say this is very bad service !