Pick and Pay Express Stores

I don't know how the shopper card of Pick and Pay supposed to work at the Pick and Pay Express. I have fill in now for many times at the Pick and Pay Express store in ******* Street Unitaspark in Vereeniging. My shopper's card was already in use and I use it many time at pick and pay. Every time I fill upt my tank at the BP garage they asked for my shopper card. But I could not understand why I only see the amount for the day I received back. But the Petrol attendant did not tell me that you must re-register the card in the shop. Why? I have lost now nearly a R1000 because nobody informs me that I need to re-register in the store. I am very disappointed. Not even the shop counter persons were very help full in this regard. How will I know be refunded for all the money I have lost?