Machine shop services service near San Francisco, CA

I took my car here for what turned out to be a simple, small electrical issue. Instead, Carlos told me I needed a fuel injection flush - one of those things they upsell you too when you go to an oil change place. Only this one cost over $300! Carlos assured me that the problem was resolved. I ended up stranded at the side of a freeway two miles away. I had to get the car towed at a cost of over $150! The solution was easy, took 10 minutes, and cost me nothing at the place I towed it to. When I called Carlos to tell him I was stranded at the side of the freeway because of his poor workmanship, his attitude was dismissive, condescending, and unhelpful. He proceeded to tell me that he doesn't guarantee that his workmanship will fix the problem. Really? Imagine if your doctor treated you that way. Basically, he took my money and did nothing. I get the feeling that this place once was a good shop, but someone got greedy and dishonest. To be certain, Carlos is a good talker. He seems sincere and knowledgeable. But the emphasis here is on SEEMS.