Fixing credit score due to default

[iantja36]

My wife had forgot to make payment for a City Bank credit card a long time back. As expected this has impacted her credit score. She now wants to make the payment for the credit card but the problem is that she doesn't remember the credit card number and even her phone number has since been changed.

Is there any way that she can make the payment back now? We tried contacting the bank but didn't receive any help.