This is actually a question the vendor can take to their merchant bank.
The vendor would be set up for merchant services with a Merchant (acquiring) Bank so they can accept credit cards. That Merchant Bank would have provided them to set up some kind of terminal for them to accept credit card transactions (either swipe a card (in person) or key in the account number. As we know from being consumers, there are may different kinds of terminals out there. Their Merchant Bank would have provided them with instructions on how to key in card transactions on their terminal. The Merchant Bank would also have already provided instructions or established some kind of process to the vendor they represent on how to transmit a payment file for settlement. Their Merchant Bank would then deposit the card funds to the account your vendor has set up with their Merchant Bank to receive the funds.
Recommendation: Refer to your internal business partners who manage the merchant services for support with ow to process card transactions on the terminals and how to actually receive the funds.