It is ethical , organizational etiquette and even under specific rules governing various departments, depending on their charter and public dealings.
I hope when ever you submit any application or memo to any dept you do it by Regd AD, or Proper Receipts etc.
And such applications or memo , need to have specific notings, by the office , where you have submitted to addresses the same.
In case of WBPDCL its not different...
If you have asked them for clarification , and if they are not giving you any information in return, you can always tell them of opting for
RTI or other legal procedures .
Because its
RTI Act and non other that gives you the right to see information.
In non
RTI Application format , it is not mandatory to disclose information , but it is more volunteerly, though Transperancy was always a must law for all departments as per our constitution.
It is this reason
RTI ACT came in to being