I keep getting the “card linked to another account” error, but my card is not linked to any of my accounts. no unauthorized money has showed up on my statements either.
You need to contact customer services to resolve any account specific issues. Click help / contact bottom left of Paypal pages for options available for your country.
Or have you considered contacting Customer Service via Facebook or Twitter? You can send them a personal message from their facebook or twitter pages. It's: https://www.facebook.com/PayPal and @AskPayPal for Twitter.
Advice is voluntary. Kudos / Solution appreciated.
