Hisense battery bad

Good day I just bought a new batter of Hisense u962 it's battery just stays a day and I did charged the battery for 16 hours. What is worse I bought a new one but still the same problem still is happening. I was blaming my service provider but it seems as if the problem is with the battery because I have a contract for this phone and I was experiencing problem with the original battery which I charged for 16 hour. It seems I have to keep my phone charged and it's worse I'm not using it for any social network purposes just only for calls . Not even playing with it.