Consumer Redressal

I WANT TO FILE CASE AGAINST HTC MOBILE COMPANY. FEW MONTHS BACK I PURCHASED THIS HTC DESIRE 700 MOBILE IN RS.21,900/- BECAUSE OF CDMA AND GSM DUAL NETWORK REQUIREMENT. BUT I WAS FACING CONNECTIVITY PROBLEM WITH CDMA SIM. THE MOBILE WAS SUBMITTED TO SERVICE CENTRE 3~4 TIMES, BUT STILL MY PROBLEM WAS NOT RESOLVED. I WAS SO FRUSTRATED THAT I SURRENDERED MY CDMA NUMBER. AND NOW I AM FACING PROBLEM WITH GSM DATA. I HAD A VERY BITTER EXPERIENCE WITH HTC AND I WANT MY MONEY BACK.RS.21,900/- IS HUGE COST FOR ME. AND I DON'T WANT TO LET MY HARD EARNED MONEY GOING IN VEIN.