634.Where a person purchased movable property before 1 July 1992 and tax under Chapter II of the Retail Sales Tax Act (chapter I-1) did not apply at the time of the purchase and, after 30 June 1992 and before 1 August 1992, the person returned the property to exchange it for other movable property, tax under section 16 does not apply in respect of the purchase of the other property if the exchange is invoiced or paid for before 1 November 1992.