Misleading birthday sms sent to customers who are loyalty card members on their birthday

Spar vantage mall cape town sends misleading birthday sms's to customers on their birthday wishing them a happy birthday & because they are loyalty club members they must fetch cake. My mom was so excited when she got an sms yesterday on 25/03/2019. I wasted my petrol & went all the way to Spar Vangate mall only to find out she does not qualify. They advised & showed us on the system that she is a loyalty club member but she doesn't have points so she doesn't qualify. My question is , why did they send her that sms knowing that she does not have any points & therefore doesn't qualify, i also advised them that no where in that sms does it say that u don't qualify if you don't have points or how many points you are required to have to qualify, it just says that she must fetch cake because she is a loyalty club member. I was referred to the manager Amina Lakay who basically said that she understands the message is misleading but those are the rules, I advised her that if its on the sms they need to deliver because they sent it in writing but she refused. I then asked for the branch manger, I was advised that her name is Anely & she is off. My poor mom was so disappointed with this deception from Spar. On the counter there were many posters stating that if clients received sms's about fetching cake on their birthdays they will not get it if they are not loyalty club members, which my mom is a club member. They saw a reason to put up those posters because of the many customers who got the very same sms & went to fetch cake on their birthdays.