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I have an Amex card I closed, it was the Jet Blue card, I still have a balance on it, and have been paying off slowly, can I ask them to lower the interest rate?
If you have another card (or plan to apply for one) you could see if they have any 0% balance transfer offers. Then transfer the closed Amex's balance and pay it off over the term of the 0% offer.
You closed the card that has a balance? No bueno, at least pay them off first and then close it.