letter
Unfortunately, I think I misplaced the copy of the lettter I sent to the senator.
I used his constituent service form (available from his website). In general , I just wrote in formal business letter style. I started by briefly explaining my situation, that I my case have been waiting for almost 700 days, far more than the 350-365 days in the receipt notice. I also include my RD/ND and LIN number. Then I subtly pleaded that he or someone int his office follow up with my case if possible, and offering him to contact me directly if he nneds more information on my case. last but not least, I thanked him for all his help.
Good luck!