N72 — comlaining about nokia N72

I regret to inform u that 2nd september 2008.I purchased a NOKIA N72 from the hot spot in west patel nagar. It worked very well but now it is troubling me.
while tlking to someone it itself get off and is not getting on. I went to the shadi pur's nokia center but there they are denieng to make it correct. I am v.disappointed by this.
as it enjoys the gaurantee period. I want to replace my set as soon as possible;as your company is a reputated one
thank you.plz replace as soon as possible