The Pep Boys review: doing work not needed for car!

I went to pep boys on 10/11/2015 at 1:15pm in Brooklyn, N.Y for an engine light on. I was told I needed a tune up and the cost was $720.00. Okay. I paid. At 7:30pm, I was told the problem still exists and might need a fuel injector. I took my car home. Next day, at 8:30am, I dropped my car off. At 11:30am, I was told my fuel injectors were leaking and they had to order them. I was unable to drive home. Next day, I called at 9am, 4pm. I was told they are testing the parts to ensure they work. At 7:45pm, I received a call from pep boys telling me the problem still exists and it might be a computer problem. I don't know how much it is, but they did all this work, charged me for everything, and the problem wasn't fixed.