Incorrect Car delivered

I spoke to Penny from Avis on the 1st of November as I had to receive a Courtesy Car from Avis. I have this option on my Car Insurance with Old mutual. She explained to me that I would receive a Group F (Family car) vehicle. I told Penny that the correct car I should receive is a Group G/H (Premium car) I even went and checked my Old Mutual Insurance Policy documents and confirmed my Car hire type was Group F Premium. Penny refused to log the correct car on the system. She said that Old Mutual advised them to issue a Group F car? On the 2nd of November I received the incorrect car from Avis. Very appalled and disgusted by the service from Old Mutual. I have been a customer for over 10 years. Ive paid for a Group G/H car with my Insurance premium every month and I receive a Group F car. This is unacceptable and you are robbing your customers Old Mutual. Please ensure that the correct car gets delivered today 2nd November by close of business. 17:00pm.