Can you get a little more finicky? It takes a whole 2 minutes to remove the dealer stickers from vehicles. Kindly ask the guy that details your truck before delivery if he will remove them for you, if not... figure it out yourself. Demanding money off the price for your "advertising" services is pathetic.
Driving you're truck around is probably the best advertisment for GM/Hummer, are you going to stop driving it and sue GM for unpaid advertising fees?