One thing you could do is:
1 – Login to the gamesandcasino one and change the user name – this also corresponds with the /xxxxx
2 – Then at the same time change the DominiqueGG to gamesandcasino
3 – Then change back the original gamesandcasino one in point 1 to DominiqueGG and make a post there that all your tweets will now be at http://www.twitter.com/gamesandcasino
Does that make any sense?