Bad client service

i am a ford customer, i bought a ford Eco sport in 2015. from Woodmead Ford firstly the adverti*****t of the car was wrong, i fought until i gave up, my car had a sound problem to date my car was still has the same problem. in 2017 August my car just lost power and stopped working, i took it to ford Benoni as it was still under warrant, they gave me a run around regard my warranty as it was coming to an end, finally they said its a petrol pump and they replaced it with a brand new part. last week Friday my car did the same thing, that brand new part has broken down its not even 2 years old, now ford came up with a story that their warranty for parts is 1 year, this came up after we told them that the part was changed over a year ago. I had this car from 2015 and it never had a problem (3 years). this means that the part that they replaced with was not new, otherwise it was supposed to last me longer than the period i owned the car before first the breakdown. they gave me a quote that is ridiculous to fix this problem, i even offered to pay 50% of the quoted amount they are refusing. ever since i bought this car, i've never had peace of mind, especially because they 're the ones who were doing all the services to this car. the part was replaced by them and now its broken. i am very unhappy