I bought DH a 3D printer for Christmas. Something he has been harping on about for years.
I told him when he opened it he'd need to build it up or at least go through it and make sure everything is there as it was from eBay in China and as it weighed a lot, sending it all back would be hard work. He went through it a bit and noticed one part was missing. I told him to go through it properly, check what parts weren't in it and I could contact the supplier. He kind of had a look and said "there's a few bits missing I think". I again said, well tell me which bits and I'll sort it. It's not like I could send such a vague message to the retailer saying "there's bits missing, send them but I can't tell you what". I even offered to go through it with him.
Again, he didn't. He never bothered getting round to it. Now almost 4 months after purchase he's suddenly decided it needs dealing with, moaning about it constantly, wanting me to send messages and get the bits that he still hasn't actually noted down! He won't shut up about it!
AIBU to say, you had your chance. I could have sent the whole thing back or at least got the parts but no way am I messing about now. Too late, pal.