False advertising

On Mr Delivery's (food) website it states that you will get R50 of your first order.

I'v registered a while ago, but never ordered anything.

When I wanted to try it, it did not give me R50 off. I ask for help in the app. They sent me a mail back, stating that, they cannot send me the discount code, as the system generated the code.

So this is false marketing / advertising. I haven't used this yet, so I have no purchases and it says on the website, you will get R50 off you first purchase. I cannot accept this response.