Who is at fault in this small car collision?

I was driving into a convenience store parking lot and was going to park in a parking spot on the other side of a truck when the driver of the truck without signal and without looking reversed going at least 25km/hr into the front of my car as I honked and yelled to tell him he was going to hit me. After we both got out of our vehicles he told me he was extremely sorry and that he will take care of everything because it was his fault and that he wasn't even looking. Now a week after the accident, I have gotten a quote from my mechanic for the damage and he is now refusing to pay it. Is it too late to go through my insurance and will my insurance go up (first time anything like this has ever happened, I am a new driver) and what else can I do at this time? Should I contact police? Thanks in advance!