Pathetic service from FedEx

Parcel ***, my parcel arrived in South Africa beginning of December, it was then cleared from customs and I received an invoice of R594.27 from FedEx. I made payment on 15/12/2023. On 18 December I received an email that my parcel is out for delivery, the package was never delivered. I called FedEx today and I was told that the invoice was incorrect and I need to pay more money. I have not received the new invoice and they expect me to make payment. FedEx service has always been unsatisfactory but now they are worse. I never use FedEx ever again.