The official GAME Twitter account has mentioned that reward point cards are now being accepted again (assuming you didn’t flog yours to ShopTo), although currently it’s just against pre-owned stock as the administrators start to figure things out.
“Your Reward Cards have now been reactivated by the Administrators for redemption against pre-owned stock,” said the account. “This means that points can be earned on all products AND redeemed against pre-owned items as of now.”
“This only applies to Reward Cards only, at present moment.”
The same Twitter account also says that the website should be back “soon”.