Bank financed written off car

Five months ago I bought a car second hand car and it was financed by Wesbank. On Monday I took in the car for it to be serviced for 30 000km at Barloworld Madza Bruma. I was told the car doesn't have a service plan what is worse they say the car was a write OFF it doesn't have a service plan and no warranty. I called the owner of the garage who took me from pillar to post. The very same day I drove to Fairland Wesbank and I was given an email address to lodge my complain. I wrote the email the very same day to Wesbank to complain. The feedback was that they have assigned an investigator. I am still waiting. I forwarded Wesbank an email to say they must come and get the car and give me another car cause by law they are not suppose to finance written off cars. There is still no response. I am paying the car and the car is still insured.