A friend of a friend also did what HPT did. NEVER give up. Keep the original letter of complaint and re-send it to as many addresses as you can find. Admin nauzze yes, but clutter the system with stats and someone will finally acknowledge that the complaints charter is utterly utterly useless.
BTW - the friend's complaint was finally answered by a Lt Col who got the right address but used the stations name at the beginning.
Dear Squadron Leader Boscombe, - Not his name!
I apologise for your inconvenience, etc... Priceless!