Are the passports still being issued in Dusseldorf? Also how do the FCO work out their price increases for passports? Do they use the Zimbabwean inflation index?
That's cutting it very fine!
Read pin's link- you can call after 4 weeks if you haven't heard by then.
You might want to look into getting an emergency travel doc just in case you don't get your passport back in time.
Just checked, it was 2011 when it got renewed from Germany. Must be getting old, swear it felt like only a few months ago and cost only 80 odd pounds. Now they want 128