Super disappointed in this. Paid £250 for it and I have multiple parts missing, some bags don't even belong in my set! LEGO were having a bad day when my pack got made.. LEGO have told me to fill out the form for missing parts, but there's that many it'll take me ages. I bought it from the shop in London while I was on holiday and don't have a LEGO store near me, so that's not an option to take it back!
I would try writing a letter to TLG instead of filling out forms to replace your set. I have read many stories about people having really crazy issues with product quality, and TLG often responds with condolence and free replacement. They're a pretty empathetic company, so I would give that a shot. I'm really sorry that you've had to go through this with such a large and anticipated set.