A sad situation - no right of representation and bullied out of a few days' leave. A long time ago, people gave up their lives and liberty to end abuse in the workplace but it seems to be creeping back nowadays.
I managed up to 250 people at a time and believed that if you are fair with them most will be fair in return. Go easy when things are smooth and they will be there for you when it's tough. Occasionally, one will take advantage but the others usually straighten them out. As an example, one employee asked for a few days' leave for a funeral of a parent. It didn't seem enough, given the relationship, so I suggested a week and call me if you need to at the end of that. 'What about my annual leave? I'll have none left.' I suggested that it wouldn't be a problem if she was reasonable about the time off for the funeral, grieving and other things. She took the week, didn't lose leave entitlement and the whole office though that the boss was a hero. I was paid back many times over with goodwill. HR, many miles away, were never told about my slant on employee relations!
If you are harsh with people, you will lose in the end. Paid work is there to fund your life, not replace it.