Vinegar turned bad

[cokacampbell]

A while ago I made some wine that started turning into vinegar so I covered it with cloth and left it to actually turn into vinegar. The problem is that after 3/4 weeks of it sitting like that I tasted it and while the first taste was vinegar it had such a horrible aftertaste I cant imagine using it for anything! For future reference does anyone know where I went wrong? All it had in it was plums, sugar and yeast. The taste is seriously horrible!