Opel died with Covid 19

3 weeks ago I took my car to them as there was something faulty with the airbag. They refused to give me a courtesy car as they suspected I could have tempered with the airbag. After crying I was then given a courtesy car. No one calls me to give me the status of my car for 3 weeks, today on the forth week when I called I was told I can come get my car as they are still waiting for parts only arriving in March,which nothing was done but just gathering dust ,even brake pads...when I ask they then say I must no longer come get my car as they need to install them. From 2009 I have been with them but this is far the worst service I have received. I don't know what to do anymore......the courtesy car also needs a service and brake pads.