This site is a scam due to google (http://www.gutefrage.net/frage/hat-jemand-erfahrungen-mit-www-cards-exchanger-com, its in German).

I used moneystream.ru for exchanging UKASH to Liberty Reserve (and then to BitCoins ) with success (i found them on a emoney forum where they have also good feedback but i dont remember which)  and they also offer PSC->LR .

Cashing PSC and UKASH out is always very expensive (especially PSC, for UKASH you can use Neteller which is quite cheap).