Amazon debt question

I recently been charged a debt for a refund on an amazon sellers account without my side of the story because the amazon account couldnt accept my credit card inforamation to allow me to function the account properly. Althought amazon is currenlty asking me to enter a valid credit card so they can cordinaly charge me a large sum of money, my actual credit card information is still displayed but not working correctly. Is there any way i can get rid of my credit card ifnormation before they start harassing me for the debt? And try to close my account to avoid paying the debt?
Thanks, help needed.uch:

Is the debt legit?

100 dollar debt for a buyer that mishandled the item, now since they refunded the buyer the money and he still has yet to ship back the item, there is a debt on my account. What should i do?