From a comment

> He didn’t send me the money straight to my bank he sent it through quickbooks my payment processing method which takes up to a couple weeks for the money to process idk if the bank is able to reverse the transaction before the money clears

Depending on the type of card (debit or credit), this might not be noticed for some time. Let's say they paid with a stolen credit card. A company or individual might not reconcile that statement more often than once a month (when the bill comes in), at which point that $12,100 will stand out. Then they file a chargeback against you. [Intuit has a process to handle that](https://quickbooks.intuit.com/learn-support/en-us/customer-refunds-and-credits/handle-chargebacks-and-retrieval-requests-for-quickbooks/00/185789), but you will almost certainly lose the dispute. In fact [they warn you about this type of scam on their site](https://quickbooks.intuit.com/learn-support/en-us/merchant-services/prevent-credit-card-fraud/00/186257#sh-collapse7)

> Asking for a cash refund on a credit card transaction is a strong indicator of credit card fraud.
>
> In some cases, the cardholder may also file a dispute for the transaction after receiving cash, resulting in a possible chargeback to you as well.
>
> To protect yourself from this type of activity, you should refund credit card transactions only as a credit back to the same card.


Contact Intuit immediately and let them know you think the transaction may be fraudulent. Don't deal with your bank, as they are a third party to the transaction in question. Intuit can likely debit the funds back and issue a refund so if there is a chargeback they handle it directly.