Question [Q] Samsung Galaxy Quattro (Win Duos) Invalid IMEI

I purchased a new Grand Quattro from Hong Kong. But now when I start the phone it shows "Invalid IMEI". Due to which I am not able to dial or receive any calls.

I have tried inserting several different codes like *#*#3646633#*#* and *#*#889988#*#* to try to enter the Engineering Mode and reinsert the IMEI but the codes are not working. Is there any other way I can solve this problem?

Thanks for the help. . . . Your answer would be much appreciated