Pathetic service with inexperienced staff!!!

My mum hired a vehicle using a credit card that's on my FNB credit card account on 6 December 2024. She and I both have not experienced any challenges with the vehicle rental process prior but this specific rental has proven to be a pain. Firstly, Avis changed their refund process but failed to notify her, she has made numerous calls to the customer service department and requested for a manager to return a call to her as at the time all managers was on leave however up until today managers seem to be on holiday. Today she called Avis again and spoke to Nonhlanhla Masondi who was apparently transferring the call to a manager but 30 minutes later the call went unanswered and eventually disconnected. There is a R1 credit transaction that is pending on the transaction history of the credit card account which the merchant of Avis needs to contact FNB merchant authorisations to provide a code to release the transaction (as advised by FNB complaints department). This pending transaction on the transaction history (not on pending authorisations) is preventing me from closing the credit card and then proceeding with emigration. This needs to be treated as a matter of urgency as this has been going on for over a month with no resolve. My mum will be sure never to use Avis again!!!