FALSE ADVERTISING

I was told by my sister that MTN was running a promotion in March 2020 for a sim only data of 40 gig for 199, I app**** for the offer, she app**** days before me so she got hers before me but had to be returned because there were documents outstanding, days later I recieved my sim card which I am satisfied with, the problem is hers we app**** for the same product but she is getting less of what she app**** for, she has been calling MTN countless times to get the matter resolved but to no help, the contact center told her to call the sales department to get voice recordings if the sale but still we cannot get in touch with them, the phone rings with no answer. Can someone from MTN man up and help this matter resolved because it seems a sale went wrong and no one wants to take accountability.