Misrepresentation

I bought a Merc in July, they said they sorted out few stretches I noticed from the car then. The day I washed the car, immediately the stretches showed up and I notified them and they kept on saying they will book it in. When they sold me the car they said I must check everything with Ronnies, the car was taken in for a service, few later I went to Ronnies to check the next service, to my surprise I was told that the car was never serviced. In all they misrepresented their sale. They have been taking me back forth with lies and stories.