DENVER -- California regulators have fined phone giant Qwest Communications International and a subsidiary $20 million for switching the long-distance service of thousands of Californians without permission, a practice known as "slamming."

The five-member Public Utilities Commission on Thursday unanimously ruled Qwest and LCI International Communications' marketing activities during 1999 and 2000 violated the state's public utilities code.

The PUC found that Denver-based Qwest "slammed" thousands of Californians by failing to adequately supervise sales agents. The PUC also said third-party verification tapes and letters authorizing the switches were falsified.

Qwest says it has corrected the problems and calls the ruling "grossly excessive."

If you've been slammed it's important for you to know that you do not have to pay the carrier who slammed you, or your authorized phone carrier, for 30 days after you've been slammed.

After the 30 days, you have to pay for any services to your authorized phone company.

You can pay at that authorized phone company's rates -- not the slammer's higher rates. Slammers usually charge about twice as much as what your original carrier charges, according to the Federal Communications Commission.

And if you have been slammed, you can get a refund for anything above what you would have paid your authorized carrier.

To file a telephone complaint, go to www.fcc.gov/slamming.