Using Commerce Feeds module, commerce file names are being changed when importing
Go to structure/feeds importer 
Select yourproductimporter - go to mapping/.  
Go to Files:URI (commerce_file:uri) 
Click on the button below text "Rename if file exists." 
Change to "Replace" and save the importer.  That worked for me.


That will eliminate the _0 or _1.mp3 and keep the same file name as your database.