The Massachusetts Bay Transit Authority is closing one T station in Quincy Monday for 20 months as roughly $33 million in improvements are added. The Wollaston T Station will be shut down Jan. 8 as the upgrades begin. In the meantime, shuttle buses will be used to take people from the Wollaston Station to the Quincy Center and North Quincy Stations. New elevators, escalators, new bathrooms and more stairways will be added to the station.