Review Rude staff at Potong Pasir Branch

I was paying for my items at the cashier and I wanted to buy a packet of cigarette. I was told I have to go to another cashier to buy the cigarette, so I ask if I can take the cigarette from another cashier and pay together with my other items. She told me’cannot’!!! I was so confused, ask to speak o a manager or supervisor and she ask me to go to the other cashier counter. I went and was rudely told off by the cashier to go back to the same cashier where my items were. Their attitude was atrocious to the core!!! I went back and saw a guy who was the supervisor Ah Kwang. I ask him why I can’t pay my cigarette and liquor together. He said it’s the LAW!! I shop at the Bishan St 22 branch and I can pay liquor and cigarette together. He says he dont know but the LAW says Potong Pasir Branch cannot. I guess I have to check with the relevant government department to see if this is true.