Tax collected but not paid must be remitted to government; officers may issue show cause notices and impose penalty. Tax collected but not paid must be remitted to the Government irrespective of taxability of supplies. The proper officer may serve a notice to show cause why the specified amount should not be paid and why a penalty equivalent to that amount should not be imposed; after considering representations the officer will determine the amount due and the person must pay it. Interest is payable on the unpaid collected amount from the date of collection until payment. Paid amounts are adjustable against tax liability for the related supplies and any surplus shall be credited to the Fund or refunded to the person who bore the incidence.