Budget Iinsurance shame on you!

Part of my Policy is that I get a rental car while my car is in for repairs after a simple bumper bash. The Policy indicates 15 days rental. The assessor misjudged the Bumper, it could not be fixed and the panel beater had to order a new part with a 2 day delay, then when they had to fit the parts the panel beater ordered the wrong Bulbar part, a further delay of another 7 days. its now 20 days at the Panel Beater. I was just informed by Budget Insurance that I am liable for the additional days car rental ( 5 days after the effect ) even though its not my fault. And I still don't have my car back. Along the way the Panel Beater assured me that I will not be liable for the additional days car rental.