I called this number 800-347-2683 to make changes to my Discover account. It's the number listed on the back of the cards. It is possible for people to change their callback number, and falsify it so it comes up wrong. It could be someone falsifying their callback number to discover to try to phish account info from you. Don't give out private info to anyone who calls you, even if the number matches. It can be falsified. Call them back at the verified company number to make any transaction. My friend got phished (different scam, supposedly Alaska Credit Union calling) last week. It sucked.