It's obviously a printing error, and if you miss a whole chapter and have the sequence of several others confused, then I should say it's serious. I think I had a book that did something similar, once, cut away part of a chapter and put it somewhere else. If it's that bad, I'd have thought you could turn it in for a replacement.
You don't even have all the chapters? I assumed that you didn't mention the chapters after Chapter 8 because they were fine. If you want to read the rest of the book, perhaps you could get it out from a library, and Wikipedia's TAA page looks to have a pretty thorough plot summary. Alternatively (unless you think the book will increase in value, as Dear Dairy advised) then a book that badly misprinted I'd have thought could be returned for a replacement without charge.
Do you think there could be more to Prufrock Prep? It seems sort of like VFD training. I'm guessing you have no clue what im talking about, and are calling me crazy, but I have evidence. Read the following: Let’s look at the facts. Mr. Remora gave his students storied to take notes on. Day in, and day out. Note taking is a V.F.D skill. Mrs. K dragged to]wo children out by their ankles. This is how V.F.D members take Neophytes from their homes! And then there is Vice-Principle Nero. Throughout the whole book, 240 pages, you never hear anything about the Principle. Perhaps the Principle is in V.F.D. Vice-Principle was probably left in charge so he wouldn’t suspect anything. Then there’s the librarian who said coded-messages. This is definitely a V.F.D trait (Remember The Sebald Code etc.?)! We are sure the librarian is in V.F.D, and that’s she has been there a long time. Is Prufrock Prep more than meets the eye?