I'm afraid they're doing a scam exit.

  I sell books online using Satoshibox an old Payment Platform.
  I think for more than a year things were going well.
  However, since the day before yesterday, I decided to withdraw my BTCs and just can not do it!
  The page says the BTCs will be shipped at 22:59 GMT and freezes.
  I tried 3 times with the same result.