Bad service

i got a promotion code and it R 80.00 off when ordering R 100.00 or more and i app**** my code and it was confirmed that i will only pay R 33.50 but to my surprise when the driver comes with my food the discount was not loaded and i only pay R 33.50 and on the app it still says i need to R 80.00 of which it must be taken off by the promotion code that i was given. can someone have a look and fix it. i dont want any bad reputation with my account. still need to use it