Samsung Galaxy Y Pro Duos — mobile under warranty but not repaired

Address:

Vadodara, Gujarat

hi
i have a samsung galaxy y ro duos handset serial number;RZ1C435GS6P([protected]) which was bought from harish moble (new sama road vadodara) on 10/05/12.
my phone is under full warranty status in that phone i have a problem that as we keep the display near our ear the is coming from that chur chur like that so gave it for repair at samsung care ( gayatri enterprise , SB 8 , saffron complex , fatehgunj , vadodara. m:[protected])
I gave them my phone for repair on 01/04/13 bill no. [protected] at first they accepted the problem and kept the phone for repair but they gave me the phone in the same condition then again i gave them on 03/04/13 with same call number then after 5 to 6 days they call me and say that the perticular problem in each and every same handset so i asked them to either give me a new phone or give a letter stating the there is no problem in my handset authorise by samsung company.
currently may phone is at samsung care fatehgunj and they are not solving my prob lem the on 12/04/13 i complained online at samsung website service request number [protected]. then they called me on 13/04/13 and said me that there is no solution of the perticular problem so i said them to give me DO letter for a new phone so they denied so i said them to give the letter which states that is no problem in phone my phone is there at samsung care from 13 days. last option came in my mind to complain here.