NEW YORK (MainStreet -- A new survey sheds light on just how heavily some consumers rely on credit cards. The National Foundation for Credit Counseling (NFCC) said 20% of consumers were unable to make ends meet without the help of a credit card, while another 22% said they would have to alter their lifestyle if they only used cash. "Credit should be used as a convenience, not to supplement income," said Gail Cunningham, financial expert for the NFCC.