Re: Can anyone answer this?
"Suggest you either tweet the questions or send the letters via your MP."
I'd go for the letter to your MP as the most effective route if you want a Minister to actually see your complaint - whether that Minister actually does anything as a result is of course a moot point.
Letters from the public to HMG Ministers are treated in one of two ways. If the letter is direct to the Minister (or his office or an official in the Department) then the Minister never actually gets to see it. It is handled only by officials (this is known as "treat official"). If, however, the same letter is sent to an MP and is then forwarded by that MP to a responsible Minister for reply, then the Minister will get it in his red box along with a draft reply (from the same official who would have replied directly as before). The Minister then signs the reply to the MP and encloses the constituent's original letter with the reply. Said constituent then gets back the official line trotted out by the Department with a nice letter from both his or her MP as well.
In my experience however, this is a largely futile exerccise unless you happen to like collecting letters from Ministers and MPs.