The first time I visited Jet at Seshego Circle ,the cashier angrily insisted that i must give the ID number for rewards

The first time I visited Jet at Seshego Circle ,the cashier angrily insisted that i must give the ID number for rewards. I did not want to give my ID as I was paying cash ,and indicated I was not interested in any rewards points ,let alone to just give my Id number to a shop of which I do not even have the store card or reward point card. I would have preferred the cashier to politely explain to me about the rewards point and why I was to give my ID as I feared for the safety of my personal information.