Alcatel 510a

I had just received this phone as a gift (Alcatel one touch 510a) and its locked (apparently)....first i have used an unlock calculator (World Unlock Codes Calculator 4.4) and inserted the code....now as i started to feel happy another dialogue box pops up, which says "SIM card Locked! Please Contact your operator! Reset Key?'' sigh....am very unhappy at this moment since this device is useless....if i can get ann help from some one, anyone it will be great full.....can someone please help me 😕