The action of crediting your account through your credit card, which may be the result of being in credit with the specific supplier for any reason: canceling a transaction, returning goods in whole or in part, overpayment, etc. For example: I get charged back by Netsal (online supermarket) whenever I return empty bottles or change a product for a cheaper one, and such.
In this case the supplier says they'll pay back expenses incurred by you but not by crediting your account through your credit card (but do charge you on it).