Bharat Petroleum [BPCL] — lpg subsidy not released and credited to my bank account

I am a regular consumer of lpg from bpcl on subsidised price and my distributors are super-chef gas services (Bharat gas distributors), t. Nagar
Chennai-600017. ([protected]@rediffmail.com). Usually, the subsidy amount would be credited on the day or after the delivery of the refilled cylinder to me, to my bank account. But, they failed to credit the subsidy as usual to my bank account for the delivery of the new refilled cylinder. On 03.03.20. I lodged a complaint with bpcl in this regard and after a lapse of nearly one month, they credited the subsidy to my bank account. But again, they have failed to credit the subsidy to my bank account for the refilled cylinder delivered to. Me on 04.05.20. Again, i lodged a complaint with bpcl regarding their failure to release the subsidy for crediting to. My bank account. They informed me via email saying that an officer from bpcl would look into the matter, but no one has taken any steps in this regard. As such, i am constrained to sue bpcl for their deliberate act. They
Are reluctant to release the subsidy due, it seems. (My cons. No.21538)