When a Visa account holder uses a Visa card to buy a pair of shoes, it's actually the acquirer—the merchant's bank—that reimburses the merchant for the shoes.
Then, the issuer—the account holder's bank—reimburses the acquirer, usually within 24 to 72 hours.
Lastly, the issuer collects from the account holder by withdrawing funds from the account holder’s bank account if a debit account is used, or through billing if a credit account is used.