Sportscene
Can't pay Laybye with RCS credit card

I went to Sandton City Sportscene to pay off the Lay-bye that my wife took there.
I wanted to pay for the lay-bye using my RCS credit card as it is accepted by Sportscene.
I got to the pay-point, took out all the necessary documents and cards. I tell the cashier what I want to do and he and a other cashier say that i cant pay for the lay-bye using my RCS card, without any explanation of why, Nothing!
What i want to know is why couldn't I pay for the lay-bye using my RCS card and why couldn't both cashiers explain to me.
I am very unhappy with the way the cashiers handled the situation.
Sort this out for me please as i don't want anything to do with Sportscene after the lay-bye is done, as it has left a bitter taste in my mouth.