Mould on Apple Leather Case

Hi, I would like to know if any of you guys here have encountered a problem where mould and fungus grew on their Apple leather case. I bought it from the Apple store about a few months ago (not exactly sure when) and used it for awhile before keeping it away in a paper bag. Only to take it out a month later and find out that mould had grown all over it.

It might be due to the fact that I do have sweaty palms, but really, did I buy a $50 case just to grow fungus at home?

Sigh, a really nice case was wasted just like that. Would be nice if anybody knows if I can contact Apple?