North Bihar Power Distribution Company [NBPDCL] — not getting bills

Address:

Third Floor, Vidyut Bhawan, Bailey Road, Patna, Patna, Bihar, 800 001

My parents live in madhepura and have an electricity connection in the name of my mother smt bimla prasad sinha having consumer id[protected]. I am paying bills online as the bills come on my email i. E. [protected]@gmail.com. Last bill was paid on 09.07.2019 and next bill that came on my mail was for (-) 1289. Naturally that could not be paid. Thereafter i have not received any bill. I have an app of yours downloaded in my mobile but every time i open the app this is the only bill, n fresh bills.
My parents are senior citizens and they can't go to office to inquire about the position. Sometime back a staff contacted them in house and told them that their connection could be cut as they are not paying bills.
As we are not getting bills since august 2019, how can the same be paid? Please do the needful.
Rajesh sinha
S/o smt. Bimla prasad sinha
Madhepura, consumer no.[protected]