The characters may look like this:
User-added image

1. Go into the Excel file of this import click File > Save As and save it as a CSV
2. Click File > Save As and save it as a CSV (Comma Separated Values)
3. Include the CSV rather than the Excel file (you may want to include CSV in the file name as it may not show in file extensions, if the file has the same name the incorrect file can be selected)
4. Duplicate original steps to run the import