How can I remove my AirTags linked to others' Apple Account and connect them to mine?

The issue you're facing is due to AirTag Activation Lock, which ties the device to the Apple Account that first paired it. Even if you bought them brand new and they were sealed, there's a chance they were somehow linked during manufacturing, demo units, or (more likely) returned/previously activated ones that were never unpaired properly.

Since you've already checked all your family's Apple Accounts through the Find My app and confirmed they're not showing there, and you’ve already exhausted Apple Support’s standard escalation route, your options narrow a bit. Unfortunately, there’s no manual override or way for even Apple Support to forcibly remove Activation Lock without the original Apple Account credentials. That’s part of their anti-stalking and anti-theft design.

Regardless, there are still a few things you can try:

• Physically reset the AirTags: Press down on the AirTag battery cover and rotate counter-clockwise to open. Remove the battery. Reinsert the battery five times, each time waiting for the sound to confirm the reset process is active (on the 5th insertion, you should hear a different tone). Replace the cover and rotate to close.
• Attempt to pair again: Bring it close to your iPhone and see if the setup card appears. If it still says it's linked to another Apple ID, proceed to the next step.
• Check all iCloud accounts you've ever used: Even if you're sure it’s not in any family members’ accounts, it’s worth logging into iCloud.com or Find My on every Apple Account you’ve ever used—especially if you might’ve tried testing the AirTag months ago and forgot.
• If purchased from a third-party or reseller: Check if they accept returns or can provide a proof of unlinking.
• Finally, if you bought them new from Apple or an Apple Authorized Reseller, escalate with proof of purchase (receipt, serial number) and clearly state that you’re the original buyer. Ask them to initiate a device unlock request—this is very rare but not impossible if you provide ownership evidence and it’s not linked to a known lost/stolen account.