I need help with the right approach to my son's principal. He is 7 and in 2nd grade. Title one reading since K?

I have always felt that the title one was not helping him but holding him back on purpose. I have him in Kumon also this year. They say he has comprehension and phonics problems. After the second quarter I called a conference with his school work getting better and they slammed me with wanting him to repeat the 2nd grade and are failing him( due to test scores) his work is 80's - 100's. His Math and spelling he has B's in. His kumon Teacher doesn't see a problem. He needs a ping grade to move on to the 3rd grade. He had an F (one point less than a D) then a D and then an F again. I don't know how to approach this without causing any further problems. I do know they ARE about keeping the funding know matter what! Any suggestions?