What are they doing at your dealer?
But when I change the oil i ALWAYS add up 8.25l, NOT 8.8l. (there is some oil left in the cooler lines etc...)
So when I add 8.25l it always shows the oil level is perfect and i keep the remaining 0.75l in my car, if it would read below mid level or read something else besides, ''OK''!
Always better to add little less then little more, you dont want oil squeezing out of your seals and gaskets.