How to Reset leather MagSafe wallet

You will first need to remove the iPhone Wallet from Find My.

To do so:

1. Open the Find My app.
2. Tap Devices and select your wallet.
3. Tap Remove This Device.
4. Tap Remove

It appears that Target sold you a returned & repackaged product that whomever had it before did not remove it from their Apple ID.

I suggest that you take it back and get a full refund. Whether or not, you want to get another one from Target, of course, is totally up to you. I would suggest that you get it directly from Apple instead.