Don't just write to your MP: phone him/her and email him/her.

I don't know how MPs operate in the UK, but here they normally have scads of staff eager to give what aid is legal or possible to any citizen who makes a point of phoning their office. Especially if they are of the party which is presently not composing the government. I have found phoning works best, as you can then interact with someone, instead of depending on the written word which may not explain the circumstances as well as possible, and inadvertently might make you sound like you are complaining about a very minor issue.

Here, each province also has a government, and my experience has been that one's MLA (Member Legislative Assembly) is usually most fitted to cope with local problems, as they aren't haring off to Ottawa all the time, and are immediately concerned.