I refused to sign the scoresheet but the arbiter signed with my initials. What should I do? I refused to sign my scoresheet, as I was planning to lodge an appeal. Yet, the arbiter signed the scoresheet with my initials. I know I didn't lose my right to object. However, I'm afraid that my appeal will be denied because the claim that I didn't sign the scoresheet will be disputed.
What should I do and how can I prove otherwise?
If the arbiter really signed with your signature, instead of his, then he just committed a crime (forgery of documents). He could have signed with his signature as proof that he confirmed the result of the game and everything on the scoresheet.
If the arbiter really forged your signature, then as a first step you should lodge a complaint against the arbiter with the tournament organizer. Next, if necessary, do the same with the federation that organizes the tournament. Depending on how serious the matters are, the police may be involved, but most likely you can solve it peacefully.
Obviously in parallel, you still put your initial claim about the game on appeals committee desk.