should they have the nerve to complain when a punter has a decent punt but still decides to leave them a negative ?
Well, yes. I can't think of a legitimate reason for leaving a negative review if the punt was decent. Obviously 'decent' is subjective, but even if the punt fell below the punter's high expectations but was still, by his own admission, decent, then surely it would rate neutral at worst, not negative. Negative should only be used for things like bait & switch, not providing services agreed, short changing on time, etc. None of them would fall under the category of decent and would rightly warrant a negative review, but a service the punter considered decent shouldn't.