Whatever you think of Jeffrey Donaldson, he has a reputation as a decent constituency MP. My wife wrote to him a couple of years ago, and he regularly sent her letters updating her on what he was hearing about her issue. ("Her issue," that sounds very mysterious, doesn't it? The thing that she wrote to him about.)
Three days after firing him off an email from the Parliament website, I got a letter back saying that he shared my concerns with Harriet Harman's comments, and would raise them with her. The letter was quite definite in its tone, which is nice. Speedy service indeed.
Of course, I doubt that it will actually change her attitude in any way, but there you go. Government can be at least slightly accessible.