Unsatisfactory assistance from Branch Manager -Cape Town International Airport

I rented a vehicle from Hertz on 20 December. I rented a vehicle from Expedia. Granwill De Koker assisted me very well and I asked him if I wanted to extend the rental for another day, he said to contact ********** and I will go straight through to the cape town international branch and someone will assist me to extend it. When I called on 21 December to extend it, the CPT International Branch Manager (cant remember her name) said to me that I am unable to extend the car for another because I was given the international rate and If I read the contract it states that I am unable to. I was so furious and told her that Granwill said we could just call and extend it for another day. This lady was so adamant that we cannot extend, I had such an argument with her, she was so rude and refused to assist us!!! I think she firstly needs to learn customer etiquette and customer service. She was so rude, we had to rush from our place to get the car back. We then took it to the Stellenbosch branch. Shermaan was so helpful and he advised me that he sees no reason why we could not extend the rental for another day! He could not see why the Branch Manager at CPT International would not assist us. He apologised for this treatment. Now I want the Branch Manager's boss to personally get her to give me a call to apologise for non-assistance and lack of customer service. If this is how she treats our fellow South Africans, how does she still treat overseas visitors. I am totally disgusted at her behaviour with not wanting to assist us while others said there was no reason for this!!!!! Totally disgusted in Hertz South Africa. Not a happy customer. Also, they charged me a deposit of R1,450 on my credit card which was actually deducted from my card when I have already paid my daily rate. This is ludicrous!!!!!!! And, a credit of 0.07 refunded to my credited card when was supposed to have been the deposit of R1,450.