I bought all of the characters that you can get for less than 1000 and I bought some of the more expesnive characters.

But now whenever I go on secret factor it says that both character-buying slots are 'sold-out'. I know I havn't got them all, I'm still missing iron-man, war-machine, vega, and loads of other characters.

Help please.

beat story mode with some of the characters you just unlocked.

Or play time attack.

mix it up and they'll be there