Why the cancellation???

Worst experience ever. Been waiting an hour for our food. Just to see that the order was cancelled on Mr Deliverys' side because one item was not available anymore, and no phone call to clarify. Why cancel the whole order? Refund the item that is no longer available.. And deliver the goods that is available. Difficult? It was a convience to use Mr.D. But the more issues occur the more it becomes an annoyance....