Ditheringdora has a good point: in cases where school refusal is not primarily to do with problems at the school, you are not helping the child by letting them stay at home.
This was the case with my dd, who went through a patch of school phobia in Yrs4-5 (separate and much worse than the crying in infants I described above). I knew that her fear was not of the school per se, or of schooling; it was of having to get up and face the unknown when she was in a frail physical and emotional state. She showed the same fear of hospital appointments, physio clinics, drama classes, family excursions etc, though obviously this was less noticeable as those didn't happen every day.
If I had given in, I would have given her the message that the only safe place for her was in bed. I don't think she would be able to walk at all by now if I had. I didn't love myself when I was manhandling a crying 10yo into her wheelchair. But I have seen what has happened to some of the kids with similar conditions who were never made to conquer their fears. They are basically in very poor physical condition; I couldn't take the responsibility for that.
We did enlist medical help as well, from the rehabilitation team at the local hospital, and that was very much about teaching her how to keep fears under control. The situation itself we can't do much about- she will always have pain and mobility problems, but it's whether you let that dominate your life or not.
OF course ours is an unusual case, but if dd was not disabled, I think I would follow the same path: first try to establish the reason for the school phobia and try to sort out any problem you can (e.g. bullying obviously has to be dealt with). Then do the broken record if need be enlist the help of a psychologist.
But the very first thing is to establish if school phobia is actual present. Most children go through a phase of crying at the start of pre-school or reception; they're not all going to grow up into school phobics. A parent's first job IMO is not to make a mountain out of a molehill. Dd's first phase of crying was not a phobia, even though the second phase, 5 years later, possibly was.