My concern here is that you refer to a "vinegar" taste. Are you describing it that way just because the acidity is pronounced, or does it actually have an acetic acid smell/flavour? If the wine is just too tart, you could definitely stabilize, clarify and sweeten to taste. However, if it actually tastes and smells like vinegar or nail polish remover, you probably have a high level of volatile acidity (acetic acid) which can be caused by oxidation or various spoilage yeasts/bacteria. Depending on temperature and other fermentation conditions, two weeks is plenty of time for the wine quickly ferment to dryness and possibly oxidize or fall prey to bacterial spoilage after sitting untopped and unstabilized for the remainder of the time. If that is the case, there isn't much that you can do about it.