Bad service One Cart and Makro

I am beyond annoyed with One Cart and Makro. I bought cooking oil and as it was my first purchase using One Cart I was happy with the ease of the app. Ordered from Makro. 12x2l Sunshine D oil. Then I get a message to ask if I wanted a substitute as the item I bought was out of stock. I choose and get told no I can't have a substitute and I will be refunded. Now what upsets me is the rudeness and tone of the 'shopper'. I am upset that I used my time and my money was deducted only to be told it is out of stock. I emailed both Makro and One Cart. No response from Makro and just a sorry from One Cart. NOT ACCEPTABLE! Today I do another order. 2 x 10l Sunfoil oil at 173.99 each. And again my payment was taken only to be told I will be refunded. I do not want a refund, I want my product I ordered. If an item is not in stock it should not be on the app. My 1st order was refunded to my wallet minus my R100 voucher. Today my order was refunded minus my R75 voucher. What the hell is this app for? To play with people's money? I want my oil!