False advertising

I recently upgrade my Telkom contract to a flexon 2 honor 400 lite with watch plus voucher as the sales man from Maponya mall advised what the package offers, however after getting the phone at the store, the watch was delivered the following week, I was told I will get an SMS for the voucher, I did not get the voucher, 2 weeks later when I follow up, I am told the is a mistake and I won't be getting the voucher, as a loyal client to Telkom for over 9 years, I am disappointed on the false advertising. I want the voucher that was promised to me