The problem I see is you have already burned some of the wood, and have just now inventoried it. I personally, could not complain if I didn't know exactly what they delivered. I do believe you likely got short changed, but knowbody knows how much. They are gonna want to know by how much you are short, and you cannot provide an answer without lying. Kind of a tough spot, I know. I bet most folks when asked how much they burn, if they do not inventory it, are off in their estimates. I have seen both sides. I know a guy that buys it delivered but just throws it in a pile. For two years in a row, I here him say he keeps getting short changed on wood. However, he decides to stack it so the wood supplier will make it right and surprise, it is what he paid for. Now, I do not know the seller, but he's gotta be getting tired off it. On the contrary, I know a guy selling "1 rick or rank of 18" wood" per truckload, but he doesn't know for sure that the amount will even fit in the bed, he just guesstimates. Well, I know for a fact it doesn't unless you pile it was over the top of the bed because I have the same size truck, 2 years newer, same bed. I dunno, maybe tell him you have concerns about the amount, but do not accuse them. Maybe they will work with you.