It's up to the panel beater

Discovery Insure uses Avis car rental. On the documentation I signed, the last date that I could get rental is 19 February (one month as per insurance agreement). I started getting SMSs since last Friday (12 Feb) that I must return the car, even though the panel beater (Dentech Strijdom Park) has not indicated to me that the car is ready. Also when I complained that it was taking too long for my car to be fixed (over a week to reassemble), I was told by phone and SMS that my car would be ready 15:30 yesterday. Halfway to fetch it (I work in Midrand, have to take a significant time off work), get phoned that the repairs had failed quality check. Was assured it would be ready to be picked up today - they'd even deliver it to me - it's 12:45 now. So I phone Discovery Insure to complain, all the agent did was give excuses for the panel beater, and passing the buck. Then he says, \what do you want me to do?\" I put the phone down. I want Customer Service!"