Hey, i just sent a case specific today,
I just said something along the time lines of
hi, i am emailing you because we recently sent in some documents and its been 4 weeks and we have no heard anything whether they were sufficient or not. I also contacted my local mp because we have been in process for 15 months but he also did not have any update for me. your response would be greatly appreciated, thank you for your time
something like that. just try to be polite and blunt, get straight to the point. they prefer emails that are concise rather than blab on and on and on. lol