Well here goes. The company I would like to choose first is one of Mumsnet's partners, so I'd better not just now.
So instead my first name and shame goes to Wincanton Home Delivery, as used by Argos and Homebase (and Comet, anyone?) whose staff have yet to learn that the delivery date they quote is NOT the delivery date we get. It is merely the delivery date to a local contractor who may take another week to deliver to our home.
Wincanton Home Delivery, as used by Argos and Homebase - train your staff properly and stop promising a service you do not deliver.