Worst car dealership/service center in history

I bought a car end of August from a friend emigrating . I then took the car for road worthy test and everything was perfect the engine everything a week and a half later on the 11/09/2020 i took the car to citroën in vaal and they were supposed to do a major service on my car which i pressumed they did until this month my car was extremely loud when it came back from the dealership and when i queried it i was told its a diesel car they sound that way but the car didnt sound so when i initially took it to them. I then barely drove with the car and in the first week of october i got a warning sign about risk filter blocking on my screen . I opened my bonnet only to find there were two pipes laying loose in the engine i called them and i told them what happened and that also my cars service light was still flickering even though they did a service . Long story short they sent one of their agents to my house and thats when i heard theres a pipe that connects the air filter to my air intake pipe is missing and the mechanic if theirs assured me they didn't work on that part however it has since come to my attention they **** to me . You cannot remove the air filter without noticing that that pipe is missing which they didnt declare as missing in their job lot but they could declare that ku clutch must be replaced and oil leak but they didnt see that. Now that i know that they worked on my air filter because its on the job lot they billed me for i know without a doubt nobody else touchesmy car and since then i have been going back and forth with them and they wont take accountability for their negligence and messiness i have copies of my correspondence with them and pictures of the pipe laying loose please help me hold them accountable for their untidy and messy work ethic . I should be back at work in cape town but i am still here because of this mess. They claiming they didnt touch my pipe yet they replaced my air filter which is connected to the pipe thats missing .