Poor service

Renault Durban South refuses to fix my damaged fuel pump under warranty, they claim it's not a mechanical fault. Where as when I sent the insurance to assess it they were told it is a mechanical fault, so hence why the insurance can't cover. I'm so angry as they have had my car for 2 weeks and on some days when I call through I'm told the lady handling my car is not at work and there doesn't appear to be anyone else who ca help me, even when a message is left for her manager 2days in a row, he never bothered to return any of my calls.