nokia mobile handset battery,model-1202

SIR,I HAVE PURCHASED NOKIA HANDET MODEL NO-1202,ON 1-1.2009,FROM SS TELECOM,2538,HUDSUN LINE,KINGSWAY CAMP,DELH110009,AFTER USING 8 MONTHS, I FIND SOME PROBLEM IN ITS BATTERY, IT BECOMES REGULAR THAT MY HANDSET GETS SWITHED OFF AUTOMATICALLY,SHOWING LOW BATTERY EVEN WHILE CHARGING,DISCONNECTION OF NETWORK,SWITCHED OFF WHENEVER I MAKE A CALL OR RECIVE THE INCOMING CALL,AND SIMILAR TYPE OF PROBLEM, AFTER CONTACTING NOKIA SERVICE CENTRE THEY SIMPLY SAYS THAT THE BATTERY IS "DUPLICATE"AND ADVICED ME TO CONTACT YOUR SELLER,AFTER SHOWING IT TO SELLER ,HE REFUSES TO SORT OUT MY PROBLEM AS THE BATTERY NO. IS NOT INDICATED IN MY BILL.I M NOW VERY UNHAPPY OF THE BEHAVIOR OF THE SELLER AND WRITING THIS COMPLAINT THE CONSUMER COURT TO SORT OUT MY PROBLEM