The corporate existence of all of such cooperative banks organized under this chapter prior to March 22, 1937, which are situated in cities, towns, and communities in which there is established and placed in operation a state or national bank or a teller's window branch thereof after March 22, 1937, shall expire and terminate not later than eighteen (18) months from the date that the state or national bank or a teller's window branch thereof opens or opened for business. However, no teller's window branch of any bank shall be placed in any incorporated town where a cooperative bank is in existence in the event a majority of the real property owners within the incorporated limits of the town or city shall protest by petition the State Bank Department's granting its permission to place a teller's window in the city or town.