PnP STOLE MY MONEY!!

I've had my SmartShopper card for some years now. I've been building my points up all the time - never used any of it. It never expired (for years). Never did I see any notification on the end of my till slip notifying me that my points expire after one year. Suddenly when I made a purchase in January, and checked my till slip, I noticed that most of my points are gone!! And just beneath that is suddenly a message saying that the points expire after a year. I e-mailed PnP customer services about this and still no reply from anyone! Today, I made another purchase, and even MORE of my points are gone and I barely have ANYTHING left of what I had built up over the years. I had almost R500 in rand value on my SmartShopper card and that is almost all gone. PnP are *******!!