Expired tropika juice at Lephalale mall pick n Pay shelves

I have bough expired tropica juice at pick n Pay lephalale mall I've tried to return them they said that I must come back later they will search for a slip on the system since I've lost my till slip, later that day they said that I must come back today and today they said that they won't exchange the juice for me since they are unable to retrieve the slip. How do they put expired juices on the shelves and expect us to keep till slips until the grocery is finished? I want my refund or the juices must be exchanged.