New World and World Population Balancing Incentives.

[JoJo_Phantom]

That's the name of the post that promised 1 Million Gil, and 15 Days of Membership upon reaching level 30.

I received the 15 days of membership, so I know i'm part of the program.

However, I never received my Gil, and despite my best efforts through tickets, I can't get an actual response from SE. Instead I have been told how to migrate my account to another service account... Twice.

http://sqex.to/iw6

That's the link to the posting.

How do I get my free Gil?

[MistakeNot]

You need to learn to read more carefully.

The 1 million gil, and 15 days of membership is only for new characters on a New World. There hasn't been any New World for over a year since Omega and Louisoix lost their New world status.
For new characters on a Preferred world, you only get 15 days of membership and no gil.
These bonuses can only be obtained once per service account.

In short, you have not been promised 1 million gil, and you are not supposed to have got any free gil.

These rules are all spelled out clearly in the post you linked to.