Car in for repairs for the past 14 months without being completed

My vehicle was collected from Newcastle on the 06th of July 2019 to be taken to Supertech Durban ARC to commence repairs after a minor accident. The repairs were completed and sent on a roll back back to Newcastle. The vehicle was returned to me on the 17th of August 2019. On delivery, some dissatisfying issues were brought to the attention of RWC Manager at Newcastle which was to be rectified when a courtesy vehicle was available. A courtesy vehicle was arranged and the vehicle was taken to Supertech Newcastle for the issues to be resolved, the vehicle had been with Supertech Newcastle before lockdown and completed unsatisfactory, now my vehicle was transported to Supertech PMB to be repaired. It has now been over 14 months that my vehicle has been in the possession of Supertech without a date given to me for delivery. In the past 14 months my instalments and insurance has costed me close to R350k, we had BMW Sa who came to Newcastle on the 21st July 2020, and after inspection said car was to be settled and returned to Supertech. The service from all departments of Supertech is appalling and definitely not up to BMW standards.