Chocolate cake for brownie

I'm very disappointed at the resolution of this issue.

I ordered a slice of cake and also selected an alternative if they dont have the cake. They delive a dry piece of chocolate...

The resolution is that they will refund me R8.99 and I should order again? Why should I place an order again and pay delivery fee again for the mistake that was done by the shop?? They should have place an out of stock next to the product...

Then another option is to drive to the shop for full refund??? I mean the reason I used the app is to save time and cost for traveling all the way to the mall for a slice of cake.