Useless lifetime guarantee for my repaired car by Keith's panel shop

I had a car accident and its a kia rio hatchback, and budget insurance took my car to Keith's panel shop in march for repairs because they could not take it to a kia approved panel shop due to costs. When the repairs were finished, and I fetched my car I noticed that on the passenger side where the repairs were done, the is an "air hissing" when driving, and when I was at home I noticed that my car had a dent less than 7cm which was badly patched with a white paint. I informed them of my issues the first incident and was told to bring the car so they can have a look at it. Which I did, the funny noise was resolved , but they refused to fix the bad painting on my car even though I was not fussing about the dent because its not big, I was told they will have to take the car to the painting bay for the painting to look neat and he walked away after saying that . The car started making the same noise, a week after they "fixed" the issue, I took the car back to them 2nd time because I was issued a Lifetime guarantee of what they fixed when budget insurance handed over the car. They sealed the window and the manager told me, there is nothing more they can do because its the wind "hitting" against the window that's making that noise. Obviously the noise is most annoying when driving on the highway and now i have to seek a panel beater shop to fix both the paint and window seal. I would not recommend this panel shop to anyone. Its pathetic.