Hi All looking for some help and share my misery

I have 2006 BMW 750Li

Had fuel leak, found out that passenger side fuel sensor lid had crack, fixed it with some epoxy. Fuel was 50% when my wife was driving the car and fuel dropped to like 10-15% range car just stuttered and died, stated again but was very shaky, jerky.

Ended up towing to a BMW mechanic

says Alterantato and battery are dead. I said battery is only 1.5 years old why don't you charge and see , next day morning i get a call, battery is ok but alternator is gone (mind that car was not starting properly, very rough idle and stuttering)

Replaced alternator at cost of $ 980 as he said if i use remanufactured one and if after installing it does not work he will have to charge me for 3 hours labor.

Next day get a call - tensioner and serpentine belt is needed , i said they were replaced only 20000 miles ago and i have FCP euro life time part replacement , so leave it i will replace it my self.

Half an hour later calls me that car computer ECM /DME needs to be replaced, So i got frustrated i said don't do anything, towed the car home.

Then realized that may be fuel sensor was not reading fuel level properly (may be there is less fuel than what it shows) so added 5 galllons of fuel and all jitteriness is gone car started driving fine.

Took the removed original alternator to auto zone they tested it and it works fine.

When car was towed we did not have key to unlock driver foot well emergency transmission lock release "to put car in neutral" some how he had put the car in neutral don't know how, but now car only goes in Drive and Neutral, can't put it in Park or Reverse. Any idea how to reenable it?

Also should i remove and give him his alternator back which he charged me $ 600 plus 3 hours of labor total of $ 938, while what car needed was just some fuel.

Auto part store tech told me that if car was not stating properly he could not decide if its alternator that was bed, he could have check fuel pressure at fuel line near fuel rail and that would have given him clue. Am i wrong in asking for refund? if he does not agree to refund me the money should i return the part to him and just dispute charges with me credit card?

Thanks