Six companies won contracts to put the arm on deadbeats for Uncle Sam. The General Services Administration awarded the two-year debt-collection contracts to: American Credit & Collection Inc. of Norwell, Mass.; ACS Accounts Management Inc., Houston.; Datacom Systems Corp., Washington; GC Services Ltd. Partnership, Houston; Nationwide Credit Inc., doing business as Credit Claims & Collections, Atlanta, and Payco American Corp. of Brookfield, Wis. The cost of the collection will be added to the debt, so the collections will be at no cost to the government.