DES MOINES &#8212 An Indianapolis telecommunications company was prohibited Wednesday from providing local telephone service in Iowa by state regulators, who said it made unauthorized changes to customers’ phone service.

The practice, known as slamming and cramming, will cost Ultimate Medium Communications Corp. $700,000 in fines, the Iowa Utilities Board said in a statement.

Slamming is when a customer’s calls are moved to another company without authorization. Cramming is causing unauthorized charges to appear on a customer’s telephone bill.

The utilities board assessed the maximum $10,000 penalty for each of 70 alleged violations of switching customer phone service.

The ruling also prohibits all Iowa telecommunications providers from billing UMCC charges to Iowa customers.

The board said UMCC did not register to do business in Iowa and failed to follow the board’s rules since it purchased Buzz Telecom in December 2006.

The utilities board also found Buzz had committed slamming and cramming against Iowans in February.

“It is possible that UMCC will not have the assets to pay all the penalties assessed,” the board’s statement said. “UMCC, however is prohibited from providing local service to customers in Iowa.”

The company’s Web site says it provides high-speed Internet service and local and long distance services.