Repair to my motorcycle R1100RT by BMW AFTERMARKET workshop

I took my BMW R1100RT to Greg at BMW AFTERMARKET, Heathway centre, Beyer's Naude St, Cresta in June 2019. I was complaining of a flat battery. Bike would not start, and does not have a kickstart. I was told to leave the bike with him. On return, I was told the battery was not good and needed a new battery. I than gave him the go ahead to fit a new battery and paid R2,060 for a new one. I was then told that not only was the battery unserviceable, but there was a problem with the starter motor. I left the bike once again with him for him to determine the problem. He than called me to say the starter motor was now unserviceable and burnt out. I than paid for a new starter or recon motor to be fitted. I was told to come collect the bike and pay the balance. I arrived at the workshop, Greg was not there, but an assistant, dealt with me and handed me the final invoice. The invoice had the price for a new battery, and a new starter motor hand written out with a grand total of R8,905-00. I rode away with my newly repaired bike, to my home. 2 days later the bike would not start, I called Greg and told him the problem. His reply was to put the battery on trickel charge. This I did, and returned the bike to shortly afterwards, with starting problems. He said, once again I was to leave the bike with him. He eventually called me back to say " somebody" had removed the new battery and put an old battery in its place. I denied such a thing and said he had not fitted a new battery in at all. He than told me to have a new battery fitted I was to give him the money for a new battery. I said I had already paid for a new battery. I continued to call him on when I could expect my bike to be ready. He kept telling me a different story about the fact that he had done extra work on the bike and had taken the new battery out and replaced the amount with labour charges. I disagreed, and said I had paid for a new battery and a new starter to be fitted as per the invoice. Months have gone passed with no results. Than come along the Lockdown, and He claimed to be in Cape And was unable to return to JHB to his workshop. About a week ago I called him to find out if he was back in town. He set up a meeting for me to come and talk about my bike. When I arrived at the workshop, I was informed that he requires R1,500 for storage for my motorcycle whilst he was away in Cape Town and whilst the bike was in his workshop since June last year. To date I still don't have my motorcycle back, and have had no response from him since.