Wrongly deduction of 450 rs

On 2/11 I had 450 Rs in my account balance and had Internet voucher of 2 gb data plan ( have aprx 100 mb left ), on 3/11 whole of my data and main balance got deducted and become zero and when I called customer care as per them I used internet and as per rule ,430 rs deducted.

I have some Question to Tata docomo and really want there reply.

1) There was no prior Information from Tata docomo company about data connection ended and due to this my main balance got empty as you know already k now a day all mobile r online always so it mean Tata docomo cheated customer by this way, if we have thousand of rs in balance they will deducted it without any information and when balance will be zero then customer will get know
It is really a Fraud as per customer view. & customer cant do any thing, it is not a question of returning 430 rs but it is Question of Ethics & customer Satisfaction

2) As per Customer care senior executive, there is some kind of rule in which if customer have lesser then 10 mb data and internet still run then there would be deduction from main balance.
This is bigger hidden condition or we can say fraud from Tata docomo company again,
There was not a single massage or mail from tata docomo company about this clause and how can a genuine customer can know this thing.