Idea Cellular India — My idea number is not converting from postpaid to prepaid and state portability

Address:	110059
Website:	idea cellular india

Its been 1 month i am in new delhi .before that i was in pune(maharastra). so i have maharashtra SIM postpaid sim and its been 1 month i have been trying to convert my SIM into delhi network and change into prepaid connection.I went to idea office many times . they have collected all the needed documents and i did everything what i was asked to do. but finally i have became that much frustrated that i am doing this.I have this number from approx 6 years. and i don't want to change my number.i am completely pissed off from there process and all that. they literally refused ny saying "ye nahi ho paega". please solve my problem. i am paying roaming charges from 1 month.