I tried to use my free 3 month apple tv trial but it does not works

The offer is tied to the purchase of a new eligible device, as purchased from Apple or an Apple Authorized Reseller. The offer should be redeemed on that new device, not on a different device (where you may have received messages about the offer). The offer is for the first user (by Apple ID account) of that new device (regardless of who bought it), and not for later users (e.g. after a reset). The offer should be redeemed within the first 3 months after activating the new device.

Read here how to redeem: Apple TV+ offer - Apple

Read here about the conditions: Apple TV+ offer - Terms and conditions - Apple

Read here if you have trouble redeeming: If you can't redeem your promotional trial of Apple TV+ - Apple Support

Bought a new iPhone12 mini that I picked up and activated 2 days ago. Thrilled that with it came a 3 month free subscription to Apple TV and noted that the free trial ended 12/17/2021.

Congratulations!

… but when I just signed in …

Signed in where? On what device? With the same account as the iPhone?

… something about a 7 day trial …

That indicates that the subscription is not active there at that time.

Verify that you subscription is still active on your account. See your subscriptions overview - Apple

Verify that you are signed in with the same account that has the subscription linked to it.

Bought a new iPhone12 mini that I picked up and activated 2 days ago. Thrilled that with it came a 3 month free subscription to Apple TV and noted that the free trial ended 12/17/2021. Started watching a show last night and continued this morning but when I just signed in to watch the next episode, I can't get it to play. I keep getting something about a 7 day trial. What happened to 3 months? Is this a scam by Apple? Feels like it.

If you qualify, and if you did as described in the guide, and you still do not get to redeem the offer, then contact Apple Support. They can look at your account and devices and assist you further.

If you qualify, then do as described in the guide.

I have tried all of those things but it still gives me the 7 day option only.

How can I get my free 3 months Apple TV for purchasing a new IPhone 11 ?