A Pennsylvania retail electricity supplier agreed to pay an $18,000 penalty to regulators and to improve its marketing practices to settle a complaint over aggressive telemarketing.

Great American Power LLC agreed to a settlement with the Pennsylvania Public Utility Commission stemming from incidents that occurred in 2012-2013 involving Great American's outside telemarketing firm. Of 20 incidents, most customers cancelled their enrollments, but four were determined to be eligible for refunds or bill credits.

The PUC's public filings were vague about exactly how the telemarketers misbehaved, saying only that Great American's review of the customer complaints showed the sales force had "exhibited unacceptable or questionable marketing practices" on the company's behalf.

Great American agreed to terminate its contract with the telemarketing firm and agreed to improve training and internal control measures over the marketing efforts. The retail energy supplier is active across the state selling electricity and gas to utility customers.

The PUC unanimously approved the settlement Thursday.