*********** staff and a nightmare rental experience

I rented out a car with tempest on the 8th of November, i was then called a week later to return the car because it was due for a service (no apology for the inconvenience caused by this), I then decided to extend the car rental for an extra 3 weeks. The person i spoke to guaranteed me that all was well and that I had to return the car back on the 21st of December per the new extension agreement. I then received a car stating that the extension was incorrect and that the car was due on the 8th of December. The person on the call told that they can't do anything to fix the problem and that i had to return the car back otherwise the risk people would come and take the car away from me. Mind you i spent R12k and that was my budget for transport. Now i am car less and yet to receive my deposit from them