Cheating on Ground of Ignorance

Location/place: Kolkata

Name of company/service: Vodafone

100 MB Rs 200 plan was activated on my Mobile in July, 2011. At the time I took the plan I made it very clear that I needed a chepest internet plan. Just a month back when I called the customer care I came to know there prevails a 1 GB internet plan for Rs 98. The same is available for everyone and even for the old customers. I asked them how can you justify a 100 MB plan at higher the price of 1 GB plan and excuse given to me was that as you are ignorant and you did not tell us we cant do it. I asked them will there be anyone who will not take a 1 GB plan at a price lower than 100 MB and request them for the refund of excess amount charged by me. Inspite of regular follow ups the replies were same and they are not ready to hear.
I am concern not only on the extra amount paid but how a Company can have such rate plans. Its simly you are selling one KG at half the price of 100 gm and as the customer of 100 gms does not know you are cheating them.