Shoprite system not taking ebucks

I went to the store, did my shopping, joined the que. When I had to pay for my goods, their till system could not recognize the FNB Ebucks card that I was using for payments of the goods I wanted to buy. I had to leave the store after I was told that their system does not take ebucks. It was not the 1st time when I had to abondon my groceries because of the same issue. I had to go to another Shoprite store, again collect the groceries, join their long ques. Why are Shoprite stores not the same?