I'm sorry you're having problems with him. What i did with Teddy when he used to pee on my bed was take him off and let him sleep in his bed, he would beg and whine to sleep with me and i would ignore him. This was when he was too little to jump on it
One time i caught him in the act so i yelled NO and made him get off right way and didn't let him get back on for a while. I guess that worked cause now he doesn't do it anymore, he jumps off and on my bed as he pleases and never pees on it at all. I hope Benji will outgrow it