Battery cycles of 404, and need to change battery as AASP

Hallo,

I have Macbook Pro 13" early 2011 (march '11) and in March 2014 my battery died completely, so I changed it for 160 USD.

Today I got a message saying; Battery to service, please change your battery at a AASP.

Once AGAIN I need to change my battery. JUST 15 months after my first battery change. This will be my third battery in 4 years.

My battery cycles are at 405 of day. Health 76 pct.

My question is, why does my battery die so insanely fast? I use it regularly, a few hours a day, making sure to full charge/full discharge, no small charges, and power is never connected, when battery is charged.

Does AASP have a warranty or something, because I really feel like I just changed my battery.

Should I change my battery, sell the macbook and buy a new macbook pro 2015? Will the battery last longer?

Bonus Info: Since 2011, I've only been using OSX 10.6.8 Snow Leopard.

I hope someone can advice me, thanks a lot!!