You must understand, even though they are a big company they do have a lot to work. Often they could be the middle man and may not have this information. Think how hard it would be managing thousands of orders while chasing up manufactures to see how the stock is going, while dealing with technical issues (I hear online shops isn't the easiest), while dealing with grabbing details of multiple shipping companies.... then a customer asking for these details and the person having to chase up all the above... or look at his screen see no new information and having to justify why to every single person who calls or emails their centre.
Yes its annoying, yes its the persons job... but lets be good blokes and leave the hard working employee's alone. So they can have a sightlier better day, if its one less call great the person has 1 less person out of their hair... but when its many, they might go home even happier. As a child show once said.... Put a smile on your dile and ill see you in a little while. Lets put a smile on the dile of the worker, be nice and give them some ease.