Hi - I had my parents' address on one of my new Disney accounts, and that's the only one that received the pin code - no accident, I'm sure. I went in immediately and updated my profile so that my correct address was reflected, and even went into my existing reservation after that with the hope that the pin email would be linked to my reservation. No such luck, since apparently the Pin code was still linked to my parents' address.
Anyway, they DID give me a hard time, but only the third time that I called. I kept calling because what we wanted (Bay Lake Tower) wasn't available, so we were debating what we wanted to do and kept making inquiries about various options. Anyway, the third time, the CM must have noticed the address difference, because he told me that I wasn't really eligible for the discount, but put me on hold to ask after I argued that the prior CM had quoted me discounted prices (entirely true). I had specific numbers, too, which may have helped, and ultimately they said that they were willing to honor it because a prior CM had quoted the lower prices. So I guess my advice would be to be prepared when you call, and have a list of what you'll book if your first, second, and third choices aren't available. I'm just saying that if the CM will book it for you the first time you call, then run with it and you won't have to deal with what happened to me after I kept calling. Good luck!