Bharat Sanchar Nigam [BSNL] — I am complaining about excess billing of landline number[protected]

Address:

srcb road, Kamrup Metropolitan, Assam, 781001

Sir
I am using this number for many years and my average monthly bill of this number 860-880 per month but since last month the company bsnl has started sending me excess bill. I. E. 3880 and 4457 approx which is very unjustified. For several months my bill amount use to be around 860-880 then how suddenly this amount has rise by 400% is not understood. Pls look into the matter. And send me a revised bill