I am an authorized user on a Chase card, that was originally opened as a Circuit City charge card, then when they went under, it was sold internally and then the credit line was immediately decreased to what was being used. I called and was told that it was simply company policy in this situation (though which situation they meant was never explained), and after a couple calls and a credit report pull of the primary cardholder, the credit line was increased from $2000 to $2800. Originally the card credit limit was for $3500 as we stood in Circuit City and got approved for an $800 television.
So, maybe it's just a matter of policy to credit chase a certain 'circumstance' or card users that you are caught in. Call them, explain that your credit situation has not gotten any worse than when they approved you for a higher limit. Ask for a reinstatement of your previous credit limit. If it's just a company policy type thing, tightening the risk factor across the board, people who call and actually talk to them and sound halfway intelligent will get a lot more consideration than those who just ignore what's happening.
Btw, just yesterday called, and got another $500 CLI to $3300 to that card no questions asked (though did pull a credit report). Asked for $5000 but said simply that she couldn't do it, and couldn't tell me why. shrug. I will call in another 6 months and expect another $500 at least.
Just a thought... making calls and talking to them makes a huge difference to big companies. And remember, if you get an idiot (which is so common in phone customer service) and you don't get the answer you like, hang up and try again.
Just my 2 kopeks worth.
I think what I'll do is this. I have this card and one other with high balances. I will wait until the baddie goes off (I keep fighting it). Then, I'll start paying off the other card, and hopefully that card won't balance chase me down. Then, with a better score and lower debt ratio, pay off the Chase card. That way, even if they lower it, I can call them, let them pull my report, and possibly get a CLI. I have around 10 inquiries, but only 2 within the last 12 months. One more shouldn't hurt me if it boosts my CL to what it was earlier.