For American Express, I had success using 877-621-2639. I checked my account last night and checked a few cards and saw the "pre-approval". I was interested in the Cash Magnet card, app'd and got the 10-14 day message (their pre-approvals need some work lol). I tried the number listed in the main thread but had a hard time getting to a human (could have been my fault). Called the above number, selected "status of application" and when they started asking for info I said "customer service", was connected to a really nice guy who approved the card for $7200 and said that I would be eligible for an increase "soon".
Since they're popular here's some helpful info if you run into issues.
For pending applications / issues with new accounts:
Bankcard Services at 800-476-4228
6am-12 midnight Monday-Saturday.
BB&T Community Bank Client First Group <BB&TCommunityBankComplaintResolutionGroup@bbandt.com> = Goes to the C-Level office
800 642 3039 - complaint resolution BBT (can't remember who provided this from here)