Bad service on asap app

Order number ***5. I bought an hth sparkle it product on their ‘asap’ app for R74, 99 and there was no option for an alternative. I then added a yoghurt so that the total amount can be over R100. The main product I wanted was the sparkle it. I was then surprised to see on the app that it was sold out after they had debited my account and accepted the order. It effectively meant that I paid a delivery fee of R35 for a mere yoghurt which was not even the main product. Why not check product availability before debiting account and accepting order? Why not give me the option to cancel order before debiting my account? They gave me a credit on the app but I wanted the funds on my account which would take 3-5 days yet they debited my account immediately. This is really frustrating. I could have used the funds to purchase the same product at Checkers but I could not. This is poor service