I received a letter from Buffalo too, although I don't know what it is yet. It was sent to my mail management service in the USA and then I request to have it scanned so I can see what it is, but I received the notice late in the day and unfortunately, it's friday, so I won't get the scan until monday now.
I hope it says what DKA's and Pharoh's letter said. I'm guessing it does since it seems like it was sent out at the same time as theirs and we are all on the same timeline. Fingers crossed! It's funny, as I assumed I'd be getting emails from them, as it seems most people do, rather than letters in the mail and all I've received from them so far are letters.
Also, I paid my RPRF about 10 days ago too. I hadn't done it when I paid the other fees as I couldn't find it on the list and I was in a hurry at the time. I saw later that it was at the top of the list not with the other fees. I also sent a copy to the Buffalo office, so they know that I paid also, but I know that they get that confirmation from Mississauga, which received the receipt on 2/17. I didn't want to wait until they ask for it as I heard that further delays your timeline.