Its ever other year or every two years which ever way you say it its not biannual that would be be twice a year
AS said above as I typed with 1 finger!
ANY aeroplane test also counts in place of a one hour + instructional/ training flight.
Why not go and do something different or a flight from a different place dual obviously and get them to do the paperwork as well, you should have pleanty of change from £200 even after the usual big tip for the instructor