I've gotten my oil changed at this same place 4-5 times and each time I tell them specifically they can disconnect the battery so the alarm won't go off. My Headunit automatically scans in radio stations, so it doesn't bother me and won't piss them off. I do remember when I dropped my car off hearing the alarm when they first put it up, and not hearing it when I came back.
There is no excuse for a mechanic to simply cut the power wire to my alarm cause he didn't like hearing it. If that's the case and he admits it, they'll be paying for my installer to rerun the wire.(I know it's easy to do, it's the principal).
