An Aug. 27 event in Brockton will give Massachusetts National Grid customers a place to get help with utility bills and learn ways to stay cool without sending electricity costs even higher. What's happening? From 10 a.m. to 2 p.m. on Aug. 27, National Grid will host a customer assistance event at Brockton's Cape Verdean Association, 575 N. Montello St., according to The Enterprise. The session is intended to help customers sort through billing …