Abnormally noisy cabin

Hi, I sent my car to dealer for periodic maintenance oil and filter changing. I was complaining about squeaky noises when driving on rough roads and asked to be checked. As I collected my vehicle I noticed something odd, it seems the noise inside the cabin increased, I mean the ambiance noise from the road from the wheels from the wind, everything sounds louder as if a door or a window is not sealed properly. Even the horn sounded differently as I hear it inside the car. I went back to the dealer and complained but of course they didn’t take the case seriously and claimed that the noise levels are normal and where it should be but I know it’s not and my wife also confirmed the same however I can’t prove it or pinpoint the root cause of it. I was wishing that you can help me so I can go back to the dealer and prove my case or if the repair is simple I can do it myself. Thanks