They just keep messing up my car! I took it to them last year for a minor service and some repairs

They just keep messing up my car! I took it to them last year for a minor service and some repairs. They damaged my engine cooler cover and failed to fix it. Then the mechanic had the nerve to tell me he didn’t touch it, even though he worked on the engine mountings. I did my research - on a Polo GT you can’t replace the front engine mounting without removing the cooler cover. I went back to them again this year for a major service, and they left my handbrake loose. I’m thinking of getting a second opinion because they had a disabled guy working on my car. I don’t mean to discriminate, but it’s a fact that mechanics sometimes have to tighten things in confined spaces. At the very least, someone should have supervised his work. I can’t help but wonder what else they left loose, especially since they worked on the brakes and other major components.