Replaced Battery; Will not boot or charge

Hello all! I am sure that this has been asked many many times, but I am seriously lost here!

Just two days ago, I received a replacement battery from iFixit, for my iPhone 4S. Followed the guide step by step, and installed new battery. Powered it on, and the first thing I noticed was the iPhone would not boot. The Apple logo would show up, but after two seconds, would disappear, and come back, but disappear again.

I've already gone back and forth to seat the battery properly as such. But still no luck.

I am starting to realize the battery is completely discharged.

But I am not too sure.

Please Help!

P.S: Restore was impossible. Was never able to get into iOS, and hard resets do nothing.

UPDATE: I replaced the battery with the original battery that came with the phone. Phone is fine now so far. I do believe I received a bad battery. Can someone point out how I can get this issue resolved under warranty?