Error with refresh

Hi All,

I have a couple of files imported where everytime a new updated file is generated it replaces the existing one. The new file(s) that replace the old ones always removes the previous month's data. 

As a result i get the message below:

So in my visualisation i have a historical view of sales, orders and so on (sometimes previously 3 months back) and every new month i need it to replace it with the column that has replaced the old column. 

How do i get my visualisation to display what the new raw file displays everytime i refresh. For example using the screenshot above 'forecast history_Jun 21' does not exist in the new file and it will show 'forecast history_Jul 21' instead as the new raw file will only display the forecast history 3 months back

Thank you !