Buy for R50 to qualify for CashBack

Town Square Superspar has a rule that only allows you to get cash back if you purchase for R50 or over. I find this to be rather inconvenient as after following a line at the teller my items only amounted to R36.98 which means i couldnt get r100 cash back. I think this non-standard rule which spar has will influence my choice of shopping stores in future. I will rather stick to checkers- with checkers you dont even need to make a purchase