Fixing incorrect transaction on my 401k debit card

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

Using the 401k funds for personal transactions is a prohibited transaction, as you are a disqualified person with respect to the investments of the 401k.

Understanding prohibited transactions

You may be able to correct the prohibited transaction:

Correcting a prohibited transaction

Going forward, take precautions such as:

• Clearly identify the 401k debit card and the personal debit card
• Do not carry the 401k debit card along with your personal cards
• Keep the cards separate