Successfull 6P replacement due to battery issues

Ever since I purchased my Nexus 6p back in December of 2015 the battery has not been great as some of you have reported. My SOT would always be around 3.5 hours with normal usage. A few months ago I started getting random shutdowns with plenty of battery juice left. It died sometimes at 30%, 25%, 15%, 5, 10% randomly and it would not come back on again unless I plugged it in to the charger. Very frustrating since you never knew when your phone would die.

I purchased the phone via Project Fi (No longer with project Fi) so I tried my luck calling asking for help knowing that the warranty was already expired. The person that answered the phone tried to troubleshoot the phone with very basic stuff including a factory reset but still the phone would shutdown with battery > 0. Factory reset did improve things at least my phone was dying at 4%. The agent that was helping me said that there was nothing else that could be done since the warranty had expired.

For a while my phone died consistently at around 4 or 5% for a few days (Due to factory reset?) but then it was back to its old self dying just like it did before (30%, 20% .....).

So I called google again and this time I was firm telling them that the phone was dying and it was unacceptable. Told them also that I have a motorola nexus 6 with original battery and no battery issues. After leaving me on hold for a few minutes the agent came back and this time asked me for my address and told me it was going to be replaced with a refurbished one.

I already received the replacement and mailed the old one back. I can say that the phone got upgraded to 7.1.2 from 7.1.1 when I got it and noticed that I now get SOT of 5 hours + with same apps and usage as before (Getting only 3.5 hours) and the phone doesn't die until it reaches 0% as it should. Yesterday I let it go down to 1% and it was still alive.

Not sure what made them reconsider. Was it me calling multiple times or being consistently in the news about being sued because of the battery and bootloop issue? or something else? but the only thing that matters is that I got another one. I just hope that the battery doesn't start to have issues months down the road.

Also forgot to mention that the refurbished phone looks brand new. No scratches, dents or any other issues.