Help or I will kill the mechanic.-self lev.suspension

[four.8is]

ok i bought my car not too long ago and it came with self leveling susp.inactive light on...I bought it being promised they will take care of that.Now after 2 days in the shop the dealership gave me the car back with the same issue..they also had a paper showing 1800$ in repairs..wouldnt be surprised if it was a fake one.
He also said that it was working right after he picked it up from the shop but on the way to the dealership it magically broke down again BUT there is a separate small battery that operates the self leveling suspension in the back of the button that operates the suspension and if the battery is low then the suspension just stays on the middle setting being unable to move up and down.
I havent signed the service papers yet but i brought the car home since i need it for the weekend but monday is going back to them.
Now what the dealership told me sounds like major BS.What do you guys think?I have never heard of a separate button in the car having its own battery ...