Credit-card executives who were called on the congressional carpet to defend their rates say using a credit score to help determine how much interest to charge is key to their
Industry critics say it's another example of abusive, confusing credit-card practices that can push consumers deeper into debt.
And Senator Carl Levin says even customers who consistently pay on time are getting whacked by credit-card issuers that raise such rates without an adequate warning or a clear notice.
He's holding out the club of possible legislation to spur voluntary changes by the industry.
One woman told his subcommittee that her credit-card rate nearly tripled without adequate notice and that issuers send ``deliberately misleading and confusing'' information.
In some cases, just opening another account, such as a department store credit card, could trigger the downgrade in credit score, leading to higher rates.