Redundant mtn sim cards sold

I went and bought an mtn sim card at jet and had the Rica done. When I tried to use it the sim card would not work. After contacting mtn from another phone, because I could not even use the intended phone to call them, I was told by mtn that the sim cards that jet sells are old stock and that they do not work! I was told that I will have to buy another one from another shop! This is disgusting! I needed to have that phone working urgently and followed all the right steps but thanks to poor management at jet which allows redundant stock to be sold, I am left without a working phone and no time to drive to another shop to get another sim card. This is unacceptable service from jet.