I tried the following code with ur unzipper.
But it doesn't work on Android 2.3
string filepath = "jar:file://" + Application.dataPath + "!/assets/" + "/TEST.zip";
pathtoExtract = filepath;
pathtoExport = Application.persistentDataPath;
try{
ZipUtil.Unzip(pathtoExtract, pathtoExport);
}
catch (Exception err)
{
text.text = err.ToString();
}