UberEats horrible service

I ordered from UberEats a while back. On the app was a foldover meal from Mcdonalds that was priced lower than usual. This was not a surprise to me as I often get discounts on the meals I order. So I ordered it because I was attracted to the meal and the bargain. To my surprise when the order arrived it was just the foldover and not the meal. The driver proceeds to tell me that the item I selected on the app was priced incorrectly and therefore I only get the foldover and not the complete order. I was livid and told him I am not paying for something I did not order. The guy took it back but there remains this charge on my app that I need to settle. I sent a complaint to UberEats but all they could do was send me automated email responses about how i should add a card for payment of that outstanding amount. I use this app quite a bit and I am appalled at the total disregard of the customers issues. Completely disgusted by the service i received or rather the lack thereof.