Poor customer service

I had taken my car for a electrical fault to the service centre, I dropped it off, full inspection of the car for dents and scratches was done on receiving the car, the car had no dents and scratches i had just done full car respray, they only did service of the car and called me to come collect the car when I arrived and I inspected the car I found that it was scratched on the rear bumper, I inquired about it no one accounted for the scratch they told me to come back when the boss(Jacob) is around.

I booked an appointment via a call to see the boss(Jacob) they told me when to come with the car, I drove for more than 70km from home to have my car painted with a nail polish to fix the deep scratches, I told Jacob I was not happy, he was so rude and told me he's doing me a favour, is not his fault and I can do whatever I like, he doesn't care, he was uninterested and wouldn't allow me to formerly complain, he just walked away and wouldn't give his surname for a formal complain