Woodies comments make sense, if it became common knowledge that every problem in economy will entitle you to an upgrade in business the amount of "problems" will rise, that and the fact that I as a paying C customer would feel treated wrongly (see my earlier posts about upgrades..)
I am NOT saying that you created this problem but just that BA can't be blamed for not helping you. If the CSD didn't do anything about the problem I would get compensation, as for checking the seats to see if they are wet, you can imagine that a 3 inch thick foam seat soaks up a lot of moisture, you probably would only notice it to be wet if you sat on it....
I always feel that the nicer and the shorter the complaint is the quicker and nicer it gets resolved...