Uneven volume buttons

As I have purchased iPhone 13 and I have noticed that my volume buttons were quite uneven. So, I called to have an appointment and after reaching the service Center at time there were no one attending me. Moreover, staff was very rude, as no one was calling my case id. I asked them about my appointment and they were your appointment was at one and it is 1:08 and without even looking at the device he said it is normal and happens due to dust because dust can get everywhere.

The staff was very very rude