Still can't activate my iPhone after the iOS Update

I have an iPhone 5c and updated it to iOS 9.3 since then it asked me for the Apple ID and password it was set up with.

I tried to downgrade it to iOS 9.2.1, I updated it to the 9.3 Update that was supposed to fix this mess and I updated to 9.3.1 today and it still doesn't work.

I entered my first ID that I set the iPhone up with and it didn't work. I tried my new ID and it didn't work. I don't know what to do anymore it just won't activate.

And no I didn't buy it from someone else. I won this iPhone from a site and already asked them about it. The iPhone was never used before me!

I tried all the fixes there are and nothing works. The iPhone is not listed on my Account anymore so I can't delete it from the Cloud or anything that was suggested by Apple to fix this issue.

It still knows which ID I used last but I can't get in. What is the problem? 😟