Very bad service

I bough a car with them, first week we got problems, they took 3days to fix small problems, and then after a few months I found out that the car was in a accident which they didn't inform me about. They excuse is just we signed for the car as it is but they delivered the car 8oclock at night where you cant see any faults and dents. Driving the car for almost 10months, still waiting for the service book