Consumer Redressal

I faced a problem of excess data usage in my Vodafone post paid connection. In the month of january 2015 Vodafone offered 2G internet pack of 1GB in Rs.90/- per month for two months. When I got the bill of January, I found that they charged Rs.3299/- out of which Rs.2846/- for my data usage only. When I called their customer care they told that 1.55 GB is consumed which is just unbelievable to me. I really need help. This Vodafone people are simply making us fool specially to the post paid customers. Please help me out of this financial loss. I am really getting tensed how I will pay that much amount. It is huge for me.