CellOne — Wrong billing reference bsnl/hq/2016/em-3752

Address:

Pune, Maharashtra, 411038

Today I got a call and the Pune office forwarded mail with reference to my complaint
email reference BSNL/HQ/2016/EM-3752. in which they mention that the usage of the number cross 1.32GB where as the limit was 500 MB so they charge me @ commercial use.. They question is when there is standing instruction that whenever the usage get ends they send message saying the usage is over how can they have allowed for access usage when there is NO SUCH REQUEST to them.
More importantly they never accept there mistake. nor give any Discount to customer.
when my average billing is not exceed 75/- per month how they can fool in this month.
BSNL's cellone is a typical THUG company that is what I understood from there said mail.
I have asked them to discontinue service with immediate effect.. still I haven't received any acknowledgment on the same. mail sent to them on 15Feb 16
This is one of the best reason why people prefer Private operator than going for mess of BSNL
I am not at all satisfied with the answer by so called authorize person.
I know my limitations and also aware that I am helpless person. See if you can check my previous billing and do something in the said case

My account number is[protected]