How old are you? I would just have a calm and rational discussion with them outlining why you think public school is a better choice for you. You also might want to try listening to your parents, they may have a good reason for not putting you in public school.
Tell them they're great for wanting to do it, and you really appreciate their efforts, but that you would like more interaction and debate that a classroom setting would provide, as well as more social interaction with your peers.
I Feel homeschooling is sheltering a child. I feel children should be around children their own age. Kids learn from kids. I know there are other things kids can do to be around peers their own age, but how sad to be home all day long with your parent. I think interaction with peers your own age is important way of growth.