Unable to claim unexpired voucher

We have used Uber Eats three times now and two out of three have had issues (wrong order, one whole meal missing). Thought to give it one more try last night seeing as we received a super promo voucher which gives you R150 off if you order R300 or more. We are a family of four so that's perfect. We decided on what we want to eat (two very excited kids by now!) put in the order but when I tried to put in the promo code (RETURNZA30), I received a message saying this promo has expired. Yet the email states clearly that the promo only expires on 14/02/2021. Needless to say, I had to cancel the order and had two very disappointed kids to console. I went on UberEats' website now but there doesn't seem to be any way to contact them (only the "pre-recorded" responses to queries). I really do not have the time to try and track down a contact email / call center) if these are not provided clearly. Twice in two days that UberEats have disappointed!