I just got a 13 inch MacBook pro, and it came with a lot of default apps installed (e.g. Garageband, iMovie, numbers, keynote, pages, etc.). There were also updates available on the app store, but when I clicked the update button I got the message: "... cannot be updated because it was refunded or purchased with a different Apple ID." So what Apple ID downloaded this app other than my own? Is there a way to fix this other than deleting and reinstalling everything?
Sure, delete the app in question from the Mac and empty trash.
Then open the App Store from the account (fast user switching type of account) you want to manage updates on that Mac. Sign in to the App Store if needed with the AppleID You prefer for your updates.
Get those apps tied to the correct AppleID.