Save data to Excel C#

I've a code that read data from excel using Interop.Excel. The problem is when the second time I'm calling the write method it seems like it's being saved in another copy and just the first call actually write data to the original excel file. It looks like the interop object won't clean up properly.

This is the Read/Write methods

public class ExcelHelper
{
    Microsoft.Office.Interop.Excel.Application excelApp;
    static AppSettingsReader settingsReader = new AppSettingsReader();


    public string[,] getExcelInfo(string excelFileName)
    {

        string[,] dataArray;

        string logfileName = settingsReader.GetValue("LogFileName", typeof(string)).ToString();
        string logDirectory = settingsReader.GetValue("LogDirectory", typeof(string)).ToString();
        string logLevel = settingsReader.GetValue("LogLevel", typeof(string)).ToString();

        Logger.Log(logfileName, logDirectory, logLevel, "Getting File " + excelFileName);

        Workbook wb = excelApp.Workbooks.Open(excelFileName,null,true);
        Microsoft.Office.Interop.Excel._Worksheet xlWorksheet = (Microsoft.Office.Interop.Excel._Worksheet)wb.Sheets[1];

        Worksheet ws = wb.Worksheets[1];

        Range range = ws.UsedRange;

       dataArray = new string[range.Rows.Count, range.Columns.Count];

        string str = string.Empty;
        int rCnt = 0;
        int cCnt = 0;

        for (rCnt = 1; rCnt <= range.Rows.Count; rCnt++)
        {
            for (cCnt = 1; cCnt <= range.Columns.Count; cCnt++)
            {



                dataArray[rCnt - 1, cCnt - 1] = System.Convert.ToString((range.Cells[rCnt, cCnt] as Range).Value2);




            }
        }

        wb.Close();


        releaseObject(range);
        releaseObject(ws);
        releaseObject(wb);



       return dataArray;


    }


    public static int WritePRSIdToExcel(int PRSInt, int line)
    {


      string excelApp = ConfigurationManager.AppSettings["excelFileName"];


      //  Application excel = (Application)Marshal.GetActiveObject("Excel.Application");
        _Application docExcel = (Application)Marshal.GetActiveObject("Excel.Application");
        docExcel.Visible = false;
        docExcel.DisplayAlerts = false;

        _Workbook workbooksExcel = docExcel.Workbooks.Open(excelApp, null, true);
        _Worksheet worksheetExcel = (_Worksheet)workbooksExcel.ActiveSheet;


        Range range = worksheetExcel.UsedRange;


        string str;

        str = (string)(range.Cells[line, 3] as Microsoft.Office.Interop.Excel.Range).Value2;



        if (!(str == null))
        {

            ((Range)worksheetExcel.Cells[line + 1, 5]).Value2 = PRSInt;

            workbooksExcel.Save();
            GC.Collect();   
            GC.WaitForPendingFinalizers();
            workbooksExcel.Close(false, Type.Missing, Type.Missing);
            docExcel.Quit();
            docExcel.Application.DisplayAlerts = true;
            Marshal.ReleaseComObject(workbooksExcel);
            Marshal.ReleaseComObject(docExcel);
            Marshal.ReleaseComObject(worksheetExcel);
            Marshal.ReleaseComObject(range);

        }



        return PRSInt;


    }

This is the method to read the data that was written to to the cell:

public class GetIDNumber
{
    static AppSettingsReader settingsReader = new AppSettingsReader();



    static void Main(string[] args)
    {
        ExcelHelper excelHelper = new ExcelHelper();



        /// <summary>
        /// Log settings
        /// </summary>
        string logfileName = settingsReader.GetValue("LogFileName", typeof(string)).ToString();
        string logDirectory = settingsReader.GetValue("LogDirectory", typeof(string)).ToString();
        string logLevel = settingsReader.GetValue("LogLevel", typeof(string)).ToString();

        string excelFileName = settingsReader.GetValue("ExcelFileName", typeof(string)).ToString();
        string TeamProjectName = settingsReader.GetValue("TeamProject", typeof(string)).ToString();

        excelHelper.InitExcel();

        tfsHelper.Connect();

        string[,] dataArray = excelHelper.getExcelInfo(excelFileName);



        //handle data


        const int START_ROW = 1;
        const int PRODUCT_REQUIRMENT_TITLE_COL = 2;
        const int REQ_DESC = 3;
        const int WORKITEM_ID_COL = 4;
        const int REQUIRMENT_ACV_ID_COL = 5;
        const int RISK_COL = 6;

        int TFSId = 0;     
        int PRSId = 0;



        while (line < dataArray.GetLength(0))
        {

            line++;



                  if (!string.IsNullOrEmpty(dataArray[line, REQ_DESC]))
                  {

                                    string TfsId = string.Empty;

                                     TfsId = ((dataArray[line, 4]));

                  } 

          }






enter code here