Once you fail to pay the credit card bill, the lender will send you a notice of your delinquency and urge you pay to avoid increase in the interest. Continuous defaults will add up more interest and the lenders might ask you for a settlement. If you are still unwilling to settle the amount, the credit card issuer may challenge you in court for repayment.
The credit card debts remain on your credit report for long time and it becomes impossible to avail credit from banks. Hence, it is always to pay off your credit card debts to avoid such a difficult situation in the future.