iPad UNABLE TO ACTIVATE after erase all data and settings

Hi, I have iPad mini 2 that never been used in almost 3 years, yesterday it was on iOS 9 and i upgraded it to iOS 12 but i want to reset it, so it might looks like new then this happened.

1. I factory reset my iPad
2. Reboot > choose language > set network > prepare to active > unable to activate says "your iPad could not be activated because the activation server is temporarily unavailable". i believe it probably should shows the iCloud sign in interface.
3. Changed the network to 3 different services still not work, wait for several hours still not work
4. Tried to connect to iTunes on my Mac > the image shows exactly like this, "The iPad "My iPad" could not be activated because the activation information was invalid. Please try again later."
5. I tried also to restore 5 times still not works, luckily i backed up yesterday and try to restore those backup but still didn't work as well, it says "iTunes could not restore the iPad "my iPad" because a session could not be started with an iPad"
6. I tried all of the possibilities that everyone in this forum/the other site suggested but still have the same issue.

Is Apple really aware and try to solve this problem for sure??? Dude It seems a lot of people faced exactly the same issue like this since several years ago but still there is NO SOLUTION. I believe apple want us to upgrade our devices and buy a new one because most of it happened on older devices like iPhone 5s, iPad like me.. it *****.

Anyone please, help me. Thanks