We're having the same issue with ours. Paid for priority, wrote "Priority" in massive writing all over the package, included the receipt on the top of the application... and it's still being processed, and that's from a May 22nd biometrics appointment.
My wife emailed them, and they said it was being treated as priority.
Now she's getting worried because her arrival date is getting closer and she wants/needs a bit of time before September to sort out her moving/job.