Indian Oil Corporation [IOC] — visit of lpg service man without any prior information.

I have an indane (Company) lpg connection bearing consumer no.4277 with shanti indane gas agency [code:180127, ph:[protected]], address: wz-427, sadh nagar, palam colony, new delhi.
One person claiming to be serviceman from the gas agency visited my house with a letter from the agency, stating that he wants to inspect the gas connection. I refused to allow him to enter my house as i had no prior information regarding his visit or arrival.
Today i. E on september 29, 2020 at 1139 hrs, i received a call from mobile no.[protected], the lady on the other end threatened me that my gas connection will be suspended as i did not allow inspection/security audit of my lpg connection in time.
Regarding this, i have a few doubts, please clarify your response on the same through email.
1. During covid pandemic, is it necessary to inspect lpg household connection without prior intimation to the customer?
2. Is the company aware that, a lot o[censored]ntoward incidents are happening now-a-days using such tactics? How should we check the authenticity of inspecting staff?
3. What are the nominal charges levied on the lpg gas consumer for such inspection?
4. Is any information via sms or any other digital means provided from your side i. E indane co. To the gas agency and consumer that such inspection is to be done on such scheduled time?
Looking forward to your quick and early response.