Recognize your staff as people. Do some self reflection. There is clearly a problem when every long term/committed staff member leaves in a negative way.
Is less then a 2 year period you go through well over 30 people. You have a problem.
Staff just didn't come back because they were so unhappy. And the awful part was that this became the norm. Then having to listen to you so called management team make fun of those people was a but much. When they should have been looking at the real problem...themselves.
Look at employees as people not just a space filled.
Talk talk talk about healthy food. But your work environments are awful.
Management ignores problems.
Get it together