Having a problem getting auto title changer over to my name, what should I do legally and what are my rights to this matter?

Having a problem getting auto title changed over to my name. The note and title is under my so called friend and co-worker name. I just payed it off about 2 month ago after a 6 yr note. Now because of personal reasons that accured at work about a year ago or so he is tacking on some charges that were never agreed on.This was all verbal with no written contract between us.He is wanting $1500 something he just came up with because of 4 payments I made late within the six year which he says messed up his credit and he is also saying that I was suppose to pay I off or changed the note over to my name witin the 5th months I started paying on it.What it boils down to is he is coming up with all this excuse that were never agreed on because of personal reasons that's happened at work.About 95% of my payments were made by my banks checks. That's about the only proof I have that shows I made payments.