title: Power BI data refresh - deleted columns in Excel still present as Fields
body: <p>I have a simple Power BI dashboard which links to just one spreadsheet.  The spreadsheet contains superfluous Columns, which I have now deleted.
  However, when I refresh the data in Power BI, the Fields which were created from those Columns still exist on the right hand side.
  How do I get Power BI to recognise that those Columns / Fields no longer exist?
  I can delete them manually but I would expect there to be a sleeker option.
  Thanks</p>