African Bank R150 shopping voucher... **** or not?

Firstly before I make my complaint the branch employees are not at fault. All friendly and helpful. The complaint is against the actual bank. They offer a R150 shopping voucher if you swipe 10X. The branches who I have been to 4x are unable to assist as it does not come from them. You get an sms saying congrats you have been awarded R150 .... but no link. If I email them they tell me to go to nearest branch. So since November I am unable to claim.