Subscription is free?

I just changed my subscription from 30 to 90 days, and the mog station still tells me that the cost of the service is 0.

Also, I heard you would get your veteran rewards for 3 months as soon as you change your subscription, but I got nothing

Could Square be giving away free time now?

You get the veteran rewards as soon as the subscription payment goes through. So not until the end of your free time.