WORST SERVICE CENTER

My 2017 Ford Fiesta 1.0 ecoboost was in for repairs last year due to my cambelt that broke they replaced most of my cooling system like water pumps and thermostats and after a lot of money and a few weeks I got my car back. late that afternoon I saw blue scratches on my rear bumper and a paint chip on my front bumper I ender up fixing it myself because I was on holiday. Not that long after that I saw my engine light coming on so I send my car back to them and I had to pay for the test, they did not want to give me the papers of the test and what they saw was wrong so I had to take photos of the papers after I asked for the papers. Unfortunately I did not see that the car details of the test was not my car details and only saw it a few months ago. Now I'm seeing that my car's making a boiling sound in the water bottle so I replaced the bottle cap and also the antifreeze in the car to make sure its not that, I'm still getting the same problem. I notified them about the problem and now they want to charge me again to just have a look but the work they done and parts is still under warranty.( They told myself and my father-in-law there was a 12 month warranty on the parts and work they done)