Is this considered stealing?

So today I went to target and I saw a phone case I liked better than mine. It's a otter box defender series for the iPhone 5s. I had the otter box defender for the 5… But for I liked the otter box defender for the 5s because the regular otter box doesn't let you use your finger print. So I traded my otterbox iPhone 5 case with the new one at the store without the cameras seeing me. My case I traded looked new it just had some minor scratches and scrapes on the edges… I wanted the one for the 5s but my sister bought me the one for the 5, I had to change it. Did I steal? Should I go look for the case I traded? I feel guilty

Really? You have to ASK if that's stealing? It isn't "considered" stealing. It IS stealing. Do you think if you drove off in someone's Porsche, it wouldn't be stealing because you left your Honda there?

Yes it is stealing. And you know that, or else you would not have hidden from the cameras. Do what you need to to make it right.

Yes, it's absolutely stealing. If you wanted to do it without stealing, you'd go to the counter and ask them to exchange the cases for you. Would they do it? No. You know that. So you stole.

Theft is illegal, and your post has been reported.