Mahanagar Telephone Nigam [MTNL] — locate cheat calls from tel no.[protected]

Can mtnl help me to locate the above cheat landline number. I wrote a compliant to irtct just now referring my mobile no [protected]. Within second i got a cheat asking in poor hindi not even knowing english some details and ask for my atm card no just now another guy called. How i know the genuine persons and why these frauds are exploiting e cards and debit cards at the expense of irtct... Just now i called back those two numbers and the cheats are blocking my calls. I am expecting more cheats if i am not writing this or if service provider not respond.