Has anyone had issues with ordering from marketplace? I thought they were meant to be one of the better supermarkets but their customer service sucks balls

We order via the app on the 3rd, 13th, 23rd to take advantage of the enjoy card offer. Without fail, up to 1/3 of our order is never delivered and is usually the more expensive items.

Yesterday we ordered many items, amongst which was infant formula. Obviously the formula was never delivered as it was 'out of stock'. As soon as delivery arrived we checked the app and they had it in stock! I called to complain and they said they will call back. I've been calling every hour to see when they will call back and the reply is always "soon"