Empty promises

Thy said spend R500 or more on diesel and get a R100 restaurant voucher. Sins then i filled up 5 times and only received 1 voucher. The whatsapp said the voucher is send via mail but nothing. Then thy have rewards. The petrol tenants said the more you spend per fill up the bigger the rewards. 3 times i spend R1300 plus to fill up and still no rewards. I think thy use all this just to attrack poeple.