Just Breaks scam, illegal, undrivable San Antonio, Texas

Documented:

April 01st, 2011 at 10:30AM, I drove my Honda Civic to Just Breaks because I had experienced an episode in which my breaks seemed less responsive than usual and I wanted to get it checked out. This is the Just Breaks located on Babcock
Road in San Antonio, Texas. The gentleman who checked in my car, showed me that I needed new boots and new brake pads. I approved everything he told me needed done for $300; I also made it clear to him that that was above what I could
spend, and he said that he recommended another service for an additional fifty dollars, but that it probably wasn't necessary.

So, at 1:30PM, I get a call from this gentleman saying that they fixed the back two breaks, and pumped air in them, and then they went to the front two breaks and, for the first time, realized that they were really rusty and needed new
calibrators. He said that my car would cost $650, and when I told him I couldn't afford that, he explained that was fine, but that my car was now undrivable because the breaks wouldn't work at all.

In a nutshell, I had a little trouble when I went in, and after four hours with them, my car is now undrivable, and I literally have to open up a credit card, just to pay them.

Over the phone, the gentleman said, "So what do you want to do here?" after explaining the situation. I asked if there was any way they could undo what they did to make it undrivable and he said no, that I'd have to pick up the car one way or another. I feel like a little kid who just got bullied. 

This doesn't seem legal to me, and if I had the money to pursue a case against Just Brakes, I would.