Problem with online pass.

My gf bought me the Mass Effect trilogy for ps3. Now I'm playing ME3 but if I try to connect to EA Servers or to open the multiplayer the game ask me the Online Pass. I don't have it and if I chose "Purchase the online pass through the store" it games me an error and return me to the main menu so I cannot do anything. And on the store there isn't anymore the online pass. I readed online that now is free but the game ask me it everytime. I can't do anything about it... I've already downloaded some dlcs too...
Any idea if there is a way to do get the multiplayer to work?

Thank to anyone who'll try to help me!