This is an easy 2 step process for those struggling to retrieve an attachment and utilize that data. 

FIRST - Make sure that you are retrieving a .csv file and not .xmlx file. Zapier tools don’t play well with .xls or .xmlx to my finding.

Select your email source (Gmail for me) and choose “New Attachment”. Your trigger will be where that email is coming from ie Inbox or a specific label. Then input a search string that matches the title for that specific email. 

Once you have located the record you need. Add the next step and select Formatter by Zapier. Select utilities and choose import CSV. For the CSV file, select “Attachment: Exists but not shown”.

From there I chose to put that data into a Google sheet as my terminus. If you are adding to a spreadsheet be sure to add the columns that relate to your data first before selecting the document to parse to. Then just plug in the corresponding line items to the columns that have been created and test your Zap.

This has saved me time from copying and pasting line items to a Google sheet everyday with reports I get daily.

Hope this helps!