The business then gets a fixed period of time when they can dispute the chargeback to the customer’s bank if they think it was unfair.
For example, if the merchant has proof of delivery despite the claim the product wasn’t received, this could be submitted along with other documents to show the business fulfilled their obligations. The bank may or may not accept these, but if it does, the merchant may eventually receive the chargeback fee and transaction back.
This whole process can take weeks, months or even years depending on the complexity of the case and cooperativeness of parties. Often, the merchant and issuing bank will go back and forth with requests and documents. In the end, the card scheme might need to conclude the case if no resolution could be reached.
Consumers are generally encouraged to raise payment issues directly with the business first and only request a chargeback when those efforts have failed.
Businesses can actively prevent chargebacks by e.g. making sure transactions clearly show their business name on bank statements or encouraging customers to call if there’s any issue.
It is in the interest of the business to avoid any chargeback, as it usually incurs a significant fee for the merchant on top of the enforced refund. If too many chargebacks incur, the business may also get penalty fees and the lost income from these charges add up.