A debtor cannot keep one of his/her credit cards when s/he files for bankruptcy. If you are a debtor you must list all creditors to whom you owe money. Under the Bankruptcy Code, a debtor cannot favor one unsecured creditor over another.
Moreover, creditors will right away know you filed bankruptcy through a notice from one of the Credit Reporting Agencies. So even if you fail to list them, such agencies would keep them informed about bankruptcy filings of their clients. It is for sure that the credit card company cancels the credit card then on learning of your bankruptcy. So even if you have managed to keep one of your credit cards current and you want to keep that card, it might be impossible for you to do so.
If you do not list the credit card or all your debts, there is a possibility of the bankruptcy being delayed, or dismissed. Also, one may end up in fines or jail time if the Bankruptcy Court decides that s/he was trying to commit a fraud on the court. So, it is to be understood that you should not try to keep a credit card when filing for bankruptcy. You should list all of your debts.
It is true that a debtor can use debit card, but businesses take a deposit that is larger than the estimated charge when one use a debit card. One should be aware that s/he is forced to file bankruptcy because s/he cannot keep up with the payments on his/her debts. Credit cards are one of the major reasons why people finish up filing for bankruptcy. So it is better to keep credit card away during bankruptcy and thus avoid incurring debt again.