In order to create a CSV file, one has to follow the below procedure:

Create your data in Excel, then click on File-->Save As. Under Save As dialogue box, Go to -->Save as type, Under save as type, select CSV (comma delimited). Then Change file name if you wish to in File name box(If you wish to keep the file name as is, then you can do so, then click on the Save button. Excel will prompt you, "Some Features in your workbook might be lost if you save it as CSV (comma-delimited). Do you want to keep using that format?" Click on the Yes button. Then close the file, with Excel prompting you, Do you want to save this CSV file? Click Yes again. I hope this helps. Thanks.