Want to know its duplicate or original one

Hello,
i ve taken a new phone just before 20 days.its nokia model no-5130 express.battery back up is very bad means if i'll listen music only for 1hr,the charge will not go more than 1day..but so many of my frnds ve taken dis phone,but they ve no prlm wid that battery.and my charger's wire is so small.so face difficulties to charge my mobile.everyone who has taken dis phone,i,ve seen it their charger's wire is very long.then how mine is too small.so im doubting its original one or nt.after 15days of buying dis mobile,that volume increasing bottom was nt working,bt after some time it worked.so plz help mee how to know weather its original or not.