defective mobile sold by dealer and not replacing

i purchased new karbonn A6 mobile on 03/10/2013 .from very first day i got problem of charging and software. when i went to dealer he is not replacingthe peice. And mobile imie number is different which is memtion on box. After that i went to service centre they are not accepting this saying that, handset from banglore market any service centre in mumbai is not accepted. Because imie number is not detected. after that dealer taken my peice saying that i will service, when after service my mobile become totally defective. and he is not ready to give me service invoice.i request him to replace but he is not ready saying that what ever you want to do, you can do. Dealer- mahalaxmi mobiles, Nallasopara east. Thane 401209 maharashtra