Vodafone India — charging data while not using internet

Sir This is to inform you that i recharged my no ([protected]) with 249 for getting 1.75 gb data on 28/2/15. And i have used internet for a limited time approx max usage of 100 mb. While checking the data in evening i was shocked that am having only 203 mb balance. While enquirng with customer care they replied that i have consumed that much. To be honest, i feel frustrated that am one of your old customer and the response they given also not satisfactory. I kindly request you to do the needful Regards Premjith