Can you advise what did you do at the end?You probably should email NDVO and get an official reply for them saying to submit to them . So you would attach that new email along with the original and submit to your nearest VFS. That's what I did . However today I received a 2nd PPR email changing my visa office to Abu Dhabi. Since I've already sent it to Riyadh as per their email I am not sure what to do?