BSNL Kalyan — Mistake in Bill

Address:

Thane, Maharashtra

My Land number is 2310349 From last three month i am getting wrong bill for internet usage.I have already filed written complaint but no use.
In All bills discount on intenet usage is calculate wrongly.I take usage details from BSNL website only.
In june 2010 as per BSNL website details is as fallow
Usage Charges- Rs 4058.41
Discount - Rs 3300.09
Net Charges - Rs 758.70

In bills BSNL AO has write discount amount in charges and charges amount in discount.After showing this mistake also they repeate this three times. I have paid all bills after recalculation by me.But as BSNL never need customer they disconnect my phone from last 7 days.
Same for bill in July and Sept 2010.