klondike

I have the infamous oil consumption issue were the truck eats 2 qrts between 3k-4k miles. So far they have replaced all lifters, pistons/rings, installed a baffle and performed a decarbon. Since the last repair I made it to 4K and got the add oil message. I am told this message will appear at 2 qrts low. I added 1 qrt to extinguish light and get it to the shop. Once arrived (today) they tell me that it was overserviced (hmmm). Then the service advisor began to tell me and quote the owners manual about how I do not have an issue at all and in fact it is perfectly normal to consume oil. So my question is; if its normal then why did they spend nearly 10K dollars on parts and labor to resolve a perfectly normal non issue? I am very frustrated as I feel they know and have admitted the issue openly and have exhausted their troubleshooting abilities and instead of replacing the engine they now want to write it off as "Normal".