You can
try this one, it's my fallback and has provided some good results as far back as the Windows 98 days.
However, if Recuva couldn't find it, even with the "deep scan" option, it sounds like it got deleted and overwritten before you became aware of losing it.
Is it possible that these folders were lost before you deleted the one that you think caused the issue?
If I were you, I'd go out and get a new card right away. Where did you buy the 4GB one? There are a LOT of counterfeit ones on the market, particularly branded as Sandisk. Some counterfeit cards have a much smaller capacity than they report, so "filling" the card actually overwrites data already on it. It's a good practice to only buy memory cards from reputable brick and mortar shops, although a handful of reputable online dealers should be safe too.