Wrongfully informed

I am deeply upset with the service I received at Shoprite liquor Northam branch. My husband went to the store to buy some refreshments. When he got to the till to pay he was asked for a xtra-shavings card. when he told the cashier that I(his wife) already have one and that he is not interested in taking one, she told my husband that if he does not sign up for a xtra-savings card that he is not allowed to buy at the store. My husband asked the lady since when does it work like that and she informed him that it was instructions from her manager. I then phoned the store to speak to the manager and the put me in contact with him, John. He then also said its policy for them to sign up the customer. I asked to speak to the branch manager named William and asked to investigate this matter. He was very helpful and got back to me with what was going on and I want to thank him for the quick feedback on the matter. As for the store, we will not be visiting that store again!