Very disappointed with Pick n Pay's underhanded tactics

I am very disappointed with the way Pick n Pay is using underhanded tactics to get people to use their new asap! app. On sign-up, users are emailed a discount code - FIRSTASAP50 -which does not work. I was also given a code "R50-OFF" to use on the app - from my local store- which did not work. On the app, they give a referral code. They say that both the sharer and the person who signs up with the referral code will get R50 off each. I know of a few people who definitely signed up with my referral code. They got R50 off but I did not get any credit for referring them. I will rather use the Checkers app as they don't mislead customers. I would like a response on email