Vodafone Mini Pp Singh Telecom — pre paid no.[protected] converted to post paid by singh telecom from unknown person

sir i promila batra has use this mobile no [protected] from last three years but any unknown person came to singh telecom converted my mobile no. to post paid no. without my knowladge i complaint to vodafone office but he said that it converted to post paid by mistake of singh telecom. they give me new chip when i show him my all id proof But it would be last 7 days my no.could not working So please help me to start my mobile no as early as posible