I hate the stealers so much that I try to do all my fixes, however when the car was acting funny I just couldn't figure it out on my own.
I've changed that battery twice now; the first time because the car acted like any other car with a dead battery, no lights, wouldn't turn over, etc, so I jumped it and it seemed ok, but when it happened again a month or so later I happened to be at KMart so I went back inside and bought a new battery for under $50 IIRC. That was 4-5 years ago and it lasted me until just a few weeks ago.
This time the symptoms were a little different, I would turn the key but there would be a 2-3 second delay before the car started. Then I pulled over to use the phone one day and after sitting in auto-stop for 5 min or so the car didn't start when I put it in gear. I got out and reseated the negative cable and it started. That weekend I looked a little deeper and discovered my negative cable was seriously frayed where it connects to the tranny housing so I replaced that and thought the problem was solved (the battery tested ok with a load tester), but the "delayed starting" returned. At that point I went ahead and replaced the 12V again, just to be on the safe side since winter is fast approaching and it was probably due anyway. I haven't had any problems since. I paid about $45 for the latest battery.
Remember the car can be jumped like any other car. Just be careful with the polarity of course. And for what its worth if I am going to put a charger on the 12V I disconnect both pos and neg cables before doing so.
And yes, it's definitely time to find another dealer...