I had an ACH from my bank to another that had some screwey issues - It got debited twice, and arrived once. They credited me back the second debit. A few months later, they credited me the same amount *again*. I went into the bank the next day and told them about their error. It's been quite a while, and they still haven't taken their money back, so I'm doing exactly as the prior poster suggested, and just leaving the amount in my account.
It's up to you whether you want to do as I did and proactively contact the institution.
With WF involved, I would recommend you to solve it on the CFP side to ensure they don't screw up your relationship with WF by trying to pull the payment back. That's just my advice.