Tangential and anecdotal, but despite supposedly being the UK market leader JustEats is pretty terrible. I've used them twice in as many years and the experience was awful both times. Missing items, meat in vegetarian dishes, late delivery, cold food etc... . You can report issues via the app but have to select one of a generic list of issues and only get a paltry partial refund - think 33% off for an order that was stone cold on arrival. The app doesn't seem to be able to handle more than one issue per order. There is a well-hidden customer service chat but they don't seem to be any more flexible than the ap.