You cannot use PayJustNow at sportscene in South Africa. According to sportscene's official X (Twitter) account, the retail store offers lay-by in all stores.

South Africa's Leeuwfontein Crossing: ... Pep, Ackermans and a planned Sportscene. A strong food offering includes KFC, Debonairs, and Hungry Lion. Leeuwfontein Crossing is the fifth shopping centre ...