So you might want to wait a bit until they sort out the bugs.
edit: swapped "had" for "am having" as this is on-going
edited to add: I've now had a response from apple after mailing support. We're getting new codes. NB they do mention doing this in response to a claim, so it appears you did need to contact Apple if you had a problem!
"Before I proceed I would like to point out that Apple is aware of the issue and are working hard to resolve it ASAP...If your claim is accepted, a valid replacement code will be sent to you by email. There will be no need to submit a new claim....Please let me know if you do not receive a replacement code within 24-48 hours, as I'll be happy to look into things further for you."
They also ask for the address of the reseller, but I purchased mine from Amazon, so I just entered my address.