Maybe it is all they own? That or they clearly have a strong preference for sleepers! To actually try and meet your needs by cutting off the toes shows they are trying.

Why do you feel they are dangerous? Do they not have grippy feet? Pretty much all the sleeps I have seen for that age have the rubber grips on the bottom of the feet and that would frankly make them rather safe to walk in!

Instead of demanding pants, socks and shoes I would just flat out ask why they seem to always have her in sleepers. If it was just laziness as you say then they would send what you are asking for and not bother putting her in them, leaving you to.

I suspect they either just don't have clothes in that size or they have a reason to keep using the sleepers.

If the do not have grippy feet then put a pair of socks with grips over top and continue on with your day.