Bad Promotional discount

Placed an order with Uber eats that offered an R75 discount on purchases of R250 or more, placed my order, and paid for it via my card only to have 2 items canceled due to being out of stock - no notification from Uber Eats or even the option to pick an alternative product and the discount was not even app****!! I am not at fault here being the customer, neither is the store involved as the Uber app does not give the option to pick an alternative. Kindly note that I am still entitled to that full discount advertised, regardless if you have the product in stock or not as you do not give an alternative to pick a different product. I have had to place another order with an additional cost of the delivery and tip for the driver (he is not at fault) - I would like a refund on my 2nd delivery and the original R75 discount app**** as per the UBer app advertised offering

Uber Eats - sort your APP out and stick to the discounts and promotions that you offer!