UKPassats

So dpf light kept coming on, then engine block light, so had it diagnosed as needing new egr,garage fitted it then asked me if I had any other issues, which I didn’t, so he explained there’s now a squeal. They tried to rectify squeal, but couldn’t, saying it might disappear with use. Anyway it is still there £340 later and I didn’t have this when it went in. What could it be and where do I stand. I did have the emmision thing done 18 months ago off VW. Could I get onto them. The garage was independent who done EGR, please advise as I’m on long road trip shortly