Dishonest business practices

I had R155 worth of complimentary uber cash of which a portion was due to expire on 27 October. I placed an order on uber eats which included a "buy 1 get 1 free" promo, which saved me R152 with that restaurant promo. However, my uber cash was not app**** or utilized towards this order whatsoever. I then tried to place another order to try and utilize my complimentary uber cash, only to see that its disappeared. I do not trust the uber App after this incident. It means if I load my own wallet with uber cash using my own funds the same thing could happen. I have CANCELED & DELETED my uber/eats account with immediate effect. I don't want anything to do with Uber from hereon out.