Oil control light burns and chips in the oil tank at 2.8 CRD

We bought a used “Grand Voyager” 2.8 CRD LTD from BJ. 2007 with about 165,000km. In addition to a new brake (dishes and blocks) we had the timing belt changed and made an oil change at ATU. The oil change was a “jubilee offer” from ATU, 30 years ATU, oil change incl. filter € 29.90 – so unbeatablely favorable. When we went “on track” for the time after the oil change, suddenly the ro I immediately switched off the engine and checked the oil level with the rod, with the result that there was absolutely sufficient oil! Since the lamp also started again, we started off from an electrical problem and continued driving – you know that with the American models… When accelerating and uphill the lamp went on, downhill and when braking the lamp went off… Unusual noises the engine also has nic I have asked my workshop to find and stop the mistake, since I would like to leave myself on my warning lights. In the Wekstatt the oil pan has been removed to agree and exclude that the sieve is stuffed. Thereby several metal chips were found in the oil pan – partly “turned up” as with a lathe. I have not moved the car since then and I have requested an expert to give it to me. r is supposed to find out where the chips come from. Does anyone have experience with metal chips in the oil pan and where they might come from? Thanks for every answer… Greeting from Hamburg