A810 Motorola. — Life of battery

I am impressed with lot of features available at affordable price but unable to use any feature due to fear of heavy battery consumptions. I make four to five phone-receive five phones /receive three four messages and sending two to three messages and bettery get totaly consumed. I switch off my phone between 9.30pm tp 7.30am even then after six hours one bar disappear then after another three hour second bar get disapper and then after half an hour entire battery get drained and phone gets switched off. I had charged my battery for fully four to five hours for first two days. Now charge for three and half hours. (Time required to get phone battery fully charged. I make four to five phone-receive five phones /receive three four messages and sending two to three messages and bettery get totaly consumed. I can not think to listen FM radio or music player nor I can even think to write a single note. Not to mention to use camera or web surfing which is absolutely not possible due to heavy consumption of battery. Please come with immediate solution so as battery can have a normal life of two to three days for simple use of call and SMS. If phone is left ideal without any use battery get drained after ten to twelve hours. My dealer gave me best service firstly by replacing new battery and then he replaced the handset even this problem is faced. Now I am seriously thinking to sell this phone by discounted cost and suffer heavy loss. I hope my bettery problem get solved and I can enjoy all best features of this phone. Please reply.