So I bought an Xbox Live Gold Subscription card a couple days ago, and I didn't get around to activating it until today.
As I was scratching off the stuff covering the code, I guess I was using too sharp an object, so I was scratching the code off as well! This is a $60 card and the code means everything. I realized I accidentally I scratched off about 5 of the 25 alphanumeric code! In a panic, I phoned Xbox support and they were like, "we can't help you with that; we've received these complaints before but you'll have to take it back to the store with a receipt and hope they will exchange it for you." I did a quick check online, and it really depends on whether they're nice or not, since they don't know if you're trying to fraud them.
Anyway, I take a really close look at the 5 scratched off digits, and manage to guess with certainty two of them, one of them I was sure of it being one or the other, one's bottom of the I could guess, and one was completely scratched off. After several iterations, I managed to guess the code.
Phew.
Note to self and to all: use a dull object to scratch the cover of and be careful not to scratch the code off.