Fraudulent Company that sells cars that were in an accident and not disclosing this!

Fraudulent company. I have purchased an Audi A3 last year with this dealer and now the car has engine issues and it appears to me this car was in an accident. I am trying to even claim to get the car engine fixed and they only going to pay R3500 out of all the things that need to be fixed - When I took this policy they sworn to me that the cover for any failures will help. I really don't want this car anymore. This are the sort of things that make us end up being crooks, I have been robbed of my hard earned money - Please anyone assist me to get legal action against this company. Thank you.