Fixing incorrect transaction on my 401k debit card

I opened up a bank account with a debit card for the Solo 401k account. I just realized that I gave the debit card number to a wrong vendor who has charged me twice for a personal transaction. How do I fix this?

Answer:

First, let me remind you to treat your 401k transactions with greater caution. The 401k checkbook/ debit card and the personal debit card should be clearly identified. Also, you should not carry the 401k debit card in your wallet along with your personal debit and credit card. Keeping the 401k checkbook and debit card separately would help you to avoid mistakes such as these.

Second, review the following article on how to correct the prohibited transaction:

Correcting a prohibited transaction