Always remember if a contest holder is asking for some design changes, try and get them done as soon as possible. If you delay it for very long, contest holder might just loose interest and could choose some other designer.
Contest holders prefer to work with those designers who take their feedback seriously, adhere to the design brief and promptly reply back. If you are still unclear about their feedback, then just ask them again, they will be happy to help you.
But if a contest holder is not interested or gives less-than-positive feedback, then may be its a sign that you should call it quits on this contest. But don't worry we have tons of more contests live.