Decisions which have become final not to be reopened.

The Rent Control Court shall summarily reject any application under sub-section (2),

(3), (4), (5), (7) or sub-section (8) of section 11 which raises

■x between the same parties or between parties under whom they or any

of them claim substantially the same issues as have been finally decided or purports to have been finally decided in a former proceeding under this Act or under the corresponding provisions of any law in force prior to the commencement of this Act or the corresponding provisions of any law repealed or superseded by such law.