sending wrong sms

Last week I received a sms saying 'Edgars is celebrating your birthday by giving you a R50 voucher. Ends 29 Feb! Show voucher code ***. Thank U Card ....249538' Today I went to Claremont to use the voucher. the consultant told me that the number doesn't correspond with my cards. I must go to the service department. I showed them the sms and my cards they said yes any of my card doesnt correspond with the numbers on the sms. Pinky call the voucher department to query about this. They said it was a mistake because I cant get a voucher I am not a club member. I am very furious because I wasted my money and my time to go to the store. And to be told It was a mistake. Their mistake cost me. when the sent a sms to come and open an account. It was sent to a right person. The sms didn't say it is sent to a club member. it was sent to a wrong person but it was my number and feb is my birthday month. that is what I don't understand. I also received voucher from makro because I am their value customer. Please stop sending spam to people. I wish i can close my account with you.