yikes, dealer overfilled oil. found out after driving for 7400 miles

[Jeg Norge]

hi so i took the car in for it's first bmw free oil change (im in toronto, canada). 7,400 miles (12,000 kms) later, i decided to do a DIY oil change. i had done it twice before the first bmw free oil change. after i drained the oil i measured how much came out. i couldn't believe it. over 8 qts (7.75 L) of oil came out. WTF??? it should only take 7 qts (6.5 - 6.6L of oil for the 2009 30i engine.

before i drained the oil i checked the onboard computer and it said oil OK. after i did my DIY oil change it still said oil level OK. is the digital dipstick actually operational?

frankly im a little worried. how should i bring this up to my dealer? i dont want them to instead give me BS about "oh you can't DIY oil changes..." well, seems like the dealer hires monkeys to change oil on clients' cars. i'm a little disappointed.

advice? thanks.