well bbforks
thats what happens when you put bean counters in charge of these things. All they see is numbers going across thier desk and they have no real clue about their operations. And even though you had the numbers right there in front of you showing them you have to figure, you're just a technician trying to tell them about numbers and they don't want someone like you telling them how to run thier business. I run into this all the time myself too. To them i suppose it may be threatening or they look at you as a lower life form being a lift truck tech. I just don't know exactly what it is that makes them that way but it is annoying none the less ;o)
Maybe they need to take time to compare their data with yours to believe it.... shrugs
OR... maybe they need time to sort it out to make it look like they came up with these figures to make themselves look good instead of giving you the credit... which goes back to my original analogy above..... lower life form ;o)

In any case you can lead a horse to water but you cant make him drink nor swallow it soooooooo......

just tell them and let it go is all you can do i guess :o)