MTN is ******** people

Good day.MTN is ******** people i bought a new sim card when i put it on my phone i got this sms"Welcome!your number is 083 *** 8525 New sism recharge and use R20 today to get 1GB valid for 2 days free"i waited for this 1GB for hours i called more than five consultants they told me to switch off my phone and switch it on after 10 minutes i will get the 1GB but still i didn't get it,i called again when i call again i was told that the promotion is finished last month,i asked if the promotion is fineshed last month why did i get the sms,and why did the other five consultant did know that the promotion is finished,he didn't answer that.even now i haven't got it