Texture packs refuse to update, saying I don't have the proper amount of data despite the fact I have more than enough

I'm trying to download the update for several resource packs, but it keeps refusing, saying I don't have enough space. The thing is, I have more than enough space to accommodate all of them.  Also as a side note; when I re select them, it say I want to download two of the same pack then doubling the megabyte requirements.