SambaPOS GO Tablet's Language Handler Issues

I’m trying SambaPOS GO Tablet on iPad. I wonder if these issues are common:

  1. Turkish, English UK and English US are always there and can’t be removed or arranged?
  2. There’re languages that can’t be added into the tablets even if they are available in toffice, like Vietnamese, I tried but never shown.
  3. After new languages are added into tablets (French, German, Spanish), they can’t be removed, even if I tried to remove them from toffice, they will be still there in my iPad.

Also, can request more languages, like Korean and Japanese?