No Delivery on promised services

<p>On the 30th of March my wife upgraded 2 cellphone contracts from MTN Pavilion on the Monthly deal there was a specific special which promised a 30GB free once off data on all LTE devices purchased but we didn't receive it and the person who sold the phones to us confirmed it. I called call center and I was referred back to the store but with no luck. What can i do to get what was promised and yet not delivered. The no.s in question are ********** 136 an ********** 798</p>