*********** OR DISHONEST?

I cooked the engine of my Triton 2.5DiD. All the oil suddenly leaked out, I still don't know where from. 101,000 km on the clock, just out of guarantee. So I took it to Union Motors Shelly Beach (Mitsubishi Agents), the same people who did all my services. The day after they phone me up and say they want to clean the engine (good) and then put new oil in it to see where is the leak. Obviously, unless the leak is from the sump, which is not, they would not see a thing because the engine does not run and so the oil pump. So I refused. The day after I called them and they say that now they want to run a pressure test. Now, everybody knows you cannot do a pressure test if the engine does not turn! So I took the car away from them. But my question is: is it possible this people know less than me about motors? Or are they just trying to extract money from me with un-necessary impossible pretended operations?