Well, you had years to do this.
I'm from the UK and my friend went through the process to get his code redeemed, but he didn't need to mail anything, he had to add some photos to a support ticket.I've tried to get this process going a few times over the years, but every time I would open a support ticket, it would get closed and marked as answered with no reply from a rep. So that's nice.
Can't wait until I'm 105 in the year 2085 and try to redeem a 76-year-old code somewhere, then sue under the UN World Court for a billion Earthcoinbits or whatever is in use by then. Good times.
Time to put Digital-Deluxe packages in the store for everything that is missing from Classic to whatever.
I wish I could complain about this, since I am missing Vanilla and TBC collector's editions. :/
For all of you saying "you had 14 years", how old are TCG codes? How about NA Vanilla CE codes or the ones from the first Blizzcon? Blizzard still honors them, so why is this any different? Just because BLIZZARD screwed up folks with the EU edition, and only the EU edition, are screwed? Tying it to one EU office is BS. The function should be consolidated to one of the other EU offices and a help page put up on the Blizzard site detailing the modified procedure. The digital goods were bought and paid for and they still exist and are accessible in-game. The need to send physical parts of the CE box is also hopelessly out-dated and should be replaced with some form of the procedure use by some other users posted here. A photo showing all of the required information in one shot, including the CD-key, which Blizzard should be able to verify. It's not rocket science.
The EU, as far as I know, is pretty big on consumer rights. Seems to me there can be some official consumer complaints filed against Blizzard for this with the European Commission (or whoever is in charge of it). If they were no longer going to accept the code, this should have been announced on full blast, especially because I'm pretty sure there were unopened copies being sold for high prices and with TBC Classic just releasing, there were likely people looking to get this for the pet as the release approached. It's horrible timing for them to do this and they also handled it horribly. They need to find a way to still honor the CE versions of TBC for EU players, especially because all versions are being accepted for US players and all versions, except for TBC, are being accepted on EU. They really dropped the ball on this one and any backlash they receive, legal or otherwise, is 100% deserved.