It is impossible to say as each case is considered individually taking into consideration a number of factors. If you have good stats, have very low refund rate etc that will add weight to your case. If the tracking also shows the shipment as delivered though that is generally and end to the matter yes unless there have been other instances of buyers reportedly experiencing the same issue, if that has happened it may influence the admins to consider your version over the vendors. It's a tough call to make, all you can do is submit your resolution proposal and detail your circumstances as clearly and as succinctly as possible in a non emotive manner so the admins can easily get a grasp of what you are saying. Some people like to write novels on nonsensical emotive rambling allegations that are very hard to decipher, doing that most certainly does not help your case. Keep it simple, factual and to the point.