Indian Oil Corporation [IOC] — change of regulator

Address:

Acharya Niketan, Mayur Vihar Phase-1, New Delhi, Delhi, 110091

I am having indane kitchen gas connection. The regulator was leaking and i lodged complaint with tanushree gas agency today (12 oct 2019). The mechanic came on the same day and replaced the faulty regulator by another one but he provided a used regulator in exchange. I accepted it due to cooking urgency. I would like to know if they should supply a new one or they can provide a used regulator. The mechanic charged rs 236 for the services though he said that the replacement piece is free. Please advise the rule and if a new regulator should be provided, please have the used regulator replaced with a new one. Thanks. Sanjay dave