Online Orders - No Delivery Date

We placed an order online, on day 2 we received notification of a partial delivery. We made a call to find out the delivery date of the omitted item, and was told to call back on day 4 if we still had not received any notification. This is for a 2-5 day delivery item! How is it that online ordering and online payment can take place instantly, then the follow up, ie: providing a date for shipment could take 4 days (1 day before due delivery date) It you have an item to advertise and receive money for, you should be able to advise when the item will be shipped!!!