u/Inevitable-Walrus512

Had rear pads and rotors replaced on a VS30 2022 Sprinter van 2500 at the MB dealership. Brakes are still squeaky at low speed while coming to a full stop and the parking brake just barely holds the van on a small slope. It's been 4k miles science the job was done. I have brought the van back so they have a second look and listen to my continued issues. I also had plenty of video evidence of the squealing brakes. This is what I found, a lot of oil(?) grease (?) on and around the brake calipers. Is this a normal thing to see after the brakes job on a vehicle?