Dealer vs. Private Mechanic

Took my 2005 into the Dealer Saturday because my engine light - ((!)) and VSC lights were on.
Typically bad service. Called in first & was told I'd receive a comp scan if I asked for the manager and it would take about 15 min. Got there, was routed to a service clerk and told I needed a scan for 89.95 and the ((!)) and VSC lights were probably just low air in the tires. Found the guy I talked to on the phone and he said he'd take care of it for me. Waited an hour - walked out and saw my car sitting on the lot untouched. Guy on the phone was gone to lunch, found the service clerk - who said he'd check - got no response in 1/2 hour - found the clerk again who asked me "Do you just want to take it?" I said yes. They pull the car around - no keys of course, when I go to get into it. Guy from phone call is back from lunch - gets the keys and drives me into the shop for the scan. Scan shows one cell of hybrid battery is down to 13 (others are about at 14.5).
Guy tells me cost of replacing the battery and suggests I call Toyota, since I'm only 1000 miles past warranty. Says they'll probably help with cost. After waiting for their call....Toyota says no.
I'm fed up with the Dealer. Even though Champion changed to Autonation - it's the same wacky service and somehow I often feel like they're scamming me. Any experience with private mechanics who specialize in Prius? Please advise.

 

Thanks JC. Not thinking they scammed me this time necessarily - but with my many bad experiences in the past - have often wondered. Too many to elucidate.