The Directorate General of Central Excise Intelligence (DGCEI) has issued a show cause-cum-demand notice of over 4.6 crore Rupees to Indian Oil Corporation for not paying service tax under the head of a goods transport agency.The Additional Director-General of DGCEI said IOC has not been paying their tax properly as a goods transport agency though the company's trucks are plying on various routes for transporting the goods of IOC. DGCEI source said the oil company did not including toll charges paid to its transporters as actual expenses in the taxable value between October 2008 and September 2013.