wcj1, I agree....there may be something left unsaid here.

Further, seems, if it were me, he might have made 3-6 mo in payments right on schedule and not used the flex feature so early in his tenure with DC. I can easily see where DC predicts a high-risk profile of a) young age, b) excessive charges or up to max credit line mo after mo c) uses the flex feature mo after mo = probable loss. Very logical. Almost predictable.

Possible counter = send them a payment in full + $1000 overpayment and see if they will re-open the account w/ the credit balance. Commit to NOT use the flex for 6 mo.

Just thinking out loud here at how I might try to convince them to re-open the account. For starters, PAY THE BILL IN FULL IMMEDIATELY so they know you have capacity and ability to pay promptly.