No reply to query

I got a rental car through Outsurance. I paid R1350 deposit. I had the car for a week. I took it back to where I got it and was informed an hour later I bumped the car. I went and had a look at the car and agreed to two tiny chips on the bumper. I signed a form agreeing that the damage will be deducted from my deposit. I Got a sms on 13 Nov telling me the damage is R305 excl VAT. When I phoned 3 weeks later to find out when I will get the balance of my deposit, no-one could find me on the system. The ref number on the sms didnt even belong to me. No, 3 days later no-one came back to me even though I was promised someone will. I then contacted outsurance twice and they never came back to me either. Worst service I ever got. I will change insurances