my son is 5 1/2 and is experiencing the same thing as your child. He will be repeating K also. But he doesn't have a learner problem. I have spoken both to his teacher and SW from his school. He is just not motivated. Everyone keeps on telling me boys are not advanced as girls, and maybe he is not ready. The same thing could also apply to your child.
You say your son is repeating kindergarden. Is there a reason for this? Has he been tested for a learning disability? Since he is unable to follow instructions both at home and at school, I wonder if the school should be "testing" for this issue. I think there is more here than misbehaviour and I feel for your son. It appears he is trying so hard to please everyone, but can not do what is asked. I think you should speak to the school about having him tested for learning issues and perhaps the results will give both you and the school some answers.