The Process cannot access the file being used by another process

public void ExportToExcel(DataTable DT, string reportName)
   {
FileInfo newFile = new FileInfo(@"C:\\Reports\\" + reportName + ".xlsx");
              

                  if (newFile.Exists)
                  {
                      newFile.Delete();  // ensures we create a new workbook
                     
                  }
                  newFile = new FileInfo(@"C:\\techsoft\\Reports\\" + reportName + ".xlsx");

                  using (ExcelPackage pck = new ExcelPackage(newFile))
                  {
                      try
                      {
                          ExcelWorksheet ws = pck.Workbook.Worksheets.Add(reportName);
                          ws.Cells["A1"].LoadFromDataTable(DT, true);
                          pck.Save();
                          
                      }
                      finally
                      {
                          ((IDisposable)pck).Dispose();                                                    
                      }
                  }
            }