Terrible customer Service and rude tone

I rented a car from thrifty car rentals in Sandton on the 23th September 2015 to return it back on 29th September as my car is still for repairs. I contacted them on the 29th to extended my rental by 3 more days, this morning there was a very rude guy who came to pick up the car from my workplace, needless to say that it was embarrassing and I now had my staff on the road. I called their callcentre and they said that they tried contacting me to tell me, when I told them I didn't get any calls from them they asked me to confirm my numbers, to which they said they had an incorrect telephone.<br> <br> They didn't acknowledge their mistake and they aren't even trying to rectify it. **** rental company that's they are