Government of India — Can not book slot for vaccine

Address:	Delhi
Website:	www.cowin.gov.in/home

I am wondering how can one go about booking a slot for vaccine.
I suspect something really fishy here.

I logged in to Cowin thru web portal as well as mobile phone and checked for free slots.
At one point I could see 100 slots open. I went and attempted to register. It said it's booked.

Then in another place I refreshed the page between 3 seconds and from NA it directly changed to Booked.

What exactly is happening here? I think everyone is not getting a fair chance to book a vaccine.
Seems government has released APIs and people are using some scripts to automatically book the slots.
Even I tried to register with Paytm for notification but it also misses the notification. I don't get any notification and within seconds like fastest finger first the slot gets booked.
I am deeply disappointed with this strategy.
I have no hopes of getting ever vaccinated if this continued like this.