Location/place: hisar, haryana

Name of company/service: htc

i had purchased a mobile hand set model HTC CHACHA A 810e IMEI
NO. 355746044954039, in the month of may 2012.
with bill no. 19724 dated 25.may 2012 from mobile junction from hisar.
the hand set is not working properly,touch system is not responding
and working properly,
speed of processing is very slow, sound quality during the call is not audible,
so what can i do in this regard, i want to replace my hand set,plz
help me in this regard.
thanks, i had kocked each and every corner ie htc company, dealer, custmor care, toll free no., email everything, these all people cheated me, make fool on every contact to them