Indian Airport Internet ~ Hacking Policies Not Tweaking Systems

Few Indian Airport avail WiFi Internet Connectivity to Customers... and what I'm going to discuss about is not hacking the WiFi Network but a simple naive way to hack the Service Scheme instead and gain much more free access than provided little i.e. 30min

I found it in two cities (Delhi, Bengaluru among visited Indian Airports) till now. Both have different hardware supporting it but the same service scheme.

The Service Acts in following way:
Step.1:
You'll get an Open WiFi Network by the name of Airport which lets you to connect without any credentials.
Connect to it.
Step.2:
Open web-browser and hit any URL; this will redirect you to a single page provided by Service Provider with details of how you can get credentials for free-demo WiFi-access.
Here, you'll have to submit your Mobile Phone number, which will receive SMS of credentials for demo access.
Get the credentials.
Step.3:
Use those credentials on the same page, under login section.
You are connected to WiFi for internet access until demo-time (30 minutes) pass.

Loopholes in Service Scheme:
[] Continuous Access For Longer Duration
The more mobile numbers you can have access to...

•  give your friends/family/personal/official Mobile Numbers to gain more demo credentials... 
•  and simply ask them to forward respective SMS to you

...the more duration you can have demo WiFi access.

Now, the system don't check your MAC Address for earlier demo privileged machines...
so you don't even require anything as simple as mac-changer.

[] Parallel Access For Same Credential Set
As, I already said MAC is not checked... so suppose you have multiple WiFi enabled devices.
You can use the same credentials on all devices at the same time.
Just need to consider what is the time-frame for that credential to expire.