National Grid to refund $1.5 million to 4,500 gas customers

National Grid will refund more than $1.5 million to 4,500 residential gas customers who were wrongfully charged a more expensive rate.Under an agreement with the Attorney General's Office, the company acknowledged that customers who should have been charged at the rate for gas used for heating were charged at the higher rate for gas used for cooking and other uses. The refunds will average $330, but will vary according to the amount of gas a customer used. [...]