Tax collected but not paid: obligation to remit collected tax irrespective of appeal; interest and adjustment apply. Section 76 imposes an obligation to remit tax collected but not paid to Government, regardless of taxability of the supplies or existence of appeals. The proper officer may issue a show cause notice and, after considering representations, determine the amount due; interest as specified under the Act accrues from collection to payment. A hearing is available on written request; the officer must record reasons and issue an order within one year (excluding periods of judicial stay). Payments are adjusted against tax liability and any surplus is credited to the Fund or refunded to the person who bore the incidence.