Two big steps back

Do you even need to guess what I'm talking about? I am officially past the end of my rope.

This morning he peed all over the bedroom carpet and refused to help clean it up. Then, tonight, he left pooh and pee piles all over the bedroom carpet again refusing to help clean it up. (Note to self - time to install hardwood). When we asked him why he didn't use the toilet or the potty he said it was because he was mad at us (presumably for not giving him a diaper).

Leading up to the pooh incident he begged me for a diaper. I told him he didn't need one because he was a big boy now. He yelled, "I don't want to be a big boy!" I calmed him down by putting his potty in front of the television and putting on his favourite Caillou video. To sweeten the deal even more I gave him a lollypop to lick while he sat on the potty. I then left the room to give him some privacy and told him to call me when he was done. A little while later I heard a whizzing noise following by the door slamming. When I went upstairs to investigate, it was like walking into a crime scene -- there was pee and pooh everywhere within a three foot radius of his potty.

I'm not sure how to deal with this type of behaviour. If I get mad, he rebels even more. If I'm nice about it, he thinks I'm giving him a ticket out of potty training. If I tell him I'm disappointed he laughs at me. Should I go on?

I have no more ideas. I've tried everything and nothing works. I'm trying to be optimistic about our diaper free vacation but it's hard. Am I the only mother on earth who has a kid that refuses to toilet train. HELP!!!