Citroen c8 Engine problems

Hello friends I could despair, because I bought a c8 with just 46000 km lt seller consumption between 7 and 8 liters on 100. that didn’t work from the beginning. So I got into the workshop consumption and performance (max. 10 to 160 quite fast, then yawn after 8 km times the 170 or just over (yawn again) so I expected more lt vehicle data should be 182. The workshop found a hose the first time v the turbocharger was defective. The second time it renewed an injection nozzle, which probably had wrong values. Unfortunately no change, I now drove again 200km of which half short distance the other long distance about every time so 30 km before the long distance consumption lt BC 11,7 liter/100 after the 200 km then refuelled calculated consumption 10,75 l/100. I now need information from other c8 riders, to the data it is a 2.2 l HDI with 128 hp Bj 2003 47000km. i.e. the seller has cut me over the ear, please ask for a few dates what need currently the same vehicles or if an expert is there, what is going on with the engine, probably both defects have the same cause. Need a few tips or factual usages. Still so much to my driving style I drive as a business car a T5 TDI by 1.9l with 2.5 tons weight in urban traffic with about 9l/100.