I went in this evening and was told by the service guy that the car was low in oil and that they put another 0.4 litres in it.
I could not believe my ears. I then got the service manager and explained the whole ridiculous calamity to him and both he and the mechanic responsible went to the car and checked the oil.
It was still showing way above the top of the dip stick plastic end. The mechanic was quite shocked and swore that when he checked it, the level was low.
I then went with him to the service bay and watched while he drained over a litre of oil from the car. When he lowered it and checked it, the correct level was now showing. He felt very embarassed and bewildered.
I then challenged the service manager about this and after a few apologies, he said that I would get a good discount from my next service - so I suppose this is not so bad.
It just shows that you have to be vigilant, even when the so called 'experts' do work on your car.
Thankfully there are also no more squeaks from the front of the car since they replaced the engine mounts. I just hope that they did not put X5 ones in