Refund of registration of car

i bought a second hand car at this garage (JAC Motors Polokwane) in April, so the made a mistake of doing the changes before they do the Disc registration of the car and they ask me to do it on own as the car was supposed to be renew Disc where i come from, so i drove from Polokwane to Malamulele to do the registration as we agreed with the manager of the garage his name is Hein Werks contact *** to do it on my own i will be refunded. i went to this garage 5 times asking my money with no help. please assist me what can i do.