Hofbro and Discovery leave Client in Limbo to fund for their incompetence!!!

My car went in for accident damage repairs on 1 November 2018. An assessment was completed shortly thereafter and repairs were Aurthorised by discovery. I was told the repairs would be completed within 10 working days. After this period had passed I recieved no feedback and I had to call in for an update. I was then sent a letter dated 21 November 2018 which explained that the parts required for the repairs are on back-order and will be delivered within 21 days ( 21 December 2018). I was then told that the repairs will be completed early in the following year. I followed up during the second week of the year and I was told that the part has still not arrived. I was then sent a second letter dated 16 January stating that the part will again be delivered within 21 days. My vehicle hire with Discovery lapsed after 30 days (end November 2018). I have contacted both Discovery and Hofbro to assist me with a vehicle while mine is still undergoing repairs. The response I got from Both Discovery and Hofbro was that; "There was nothing they can do" about the whole situation. I had to hire a vehicle on my own personal account because my service providers cannot keep to the dates that they have promised. They are refusing to assist me with transport and I have to fund for their incompetence. When I call to complain, I am told to personally follow up with Nissan. Discovery and Hofbro have the worst Client service I have ever recieved!!!