Service tax exemption for GST Network services provides retrospective relief and permits refund claims subject to a filing deadline. Exempts service tax on services by the Goods and Services Tax Network to central, state and union territory administrations for the period 28 March 2013 to 30 June 2017, provides for refund of tax collected that would not have been payable had the exemption applied, requires refund claims to be filed within a prescribed period from the Finance Bill's assent, and declares that the omitted chapter of the Finance Act applies retrospectively for refund processing as if it had remained in force.