Manufacturer & the store problem

My TV had a displaying issues I brought it to the store where I bought it from, the next day I was told to come to the store because there were visible dents on the screen of which they were not there. The following week they said I must come to watch the video footage. I told them that I was in training and now I am at the store they are telling me that the video is no available. I want my TV to be fixed. I want proof and they are saying they don't have.