A debt collector violated federal law when it threatened to tell credit-reporting agencies that a woman had failed to pay a bill she was not obligated to pay, a judge ruled today. In a written opinion, U.S. District Judge Thomas M. Durkin granted summary judgment in favor of Donna M. Slick in her lawsuit against Portfolio Recovery Associates LLC (PRA). Durkin held that PRA violated the Fair Debt Collection Practices Act by making false and misleading statements in three letters sent to Slick. PRA was trying to …