2002 sunfire 2.4L a/c compressor problem

Well for awhile now I have had this loud sqeeking noise when I turn on the car or turn on the A/C going below 50 mph. I took it to the car dealership and they told me it was my compressor. They then replaced the compressor 580$. Went not more then a block away and still sqeeking. I pulled back into the dealership and they told me it could be a defective compressor. Now they tell me it is my tensioner caused because I had a bad compressor. Replacing the tensioner is like 70$ and my question is this true? I paid 580$ for something I feel I do not need if my old compressor could have lasted with a new tensioner replaced. Even if I could have got another 2 years before my tensioner went bad again because my compressor is causing it to go bad It's better then me spending all this money on something that doesnt fix my problem and that is the squeeking. Also if someone could tell me where the compressor is located in this car that would help also, thanks!

Also if someone could tell me where the compressor is located in this car that would help also, thanks!

Open the hood, on the passenger side of the motor, look for the serpentine belt. Follow the belt to the bottom front of the car, close to the radiator. The compressor is the lowest, forward mounted device connected by the belt.

It sounds to me like you may have paid a $580.00 mistake/oversight by the repair man.