I think I tried that for my first TGStore purchase-- and no go.
Pre-paid cards are a pretty good idea for online purchases considering
the weirdness that is going on around the world today. (Not alluding to
any concerns about TGC), just hackers and snoopers that try to spy and
steal ID's and such. Get calls all the time from India, China-- who knows
where?! They've even left messages in Chinese. Silly.
But sometimes they try to sound legit and get local numbers (which of
course just the last 4 change up every single time.)