Midas Muffler

abosolutely horrible, we paid $300 dollars and for a check engine light scan and replace O2 sensor, 5 days later light was on again. We went back they told us they fixed our car with a faulty part, and they replaced it sat there for hours 2 saturdays in a row with our kids... then 5 days later the light came on again.... we went back and again it was the same code... they would not give us our Money back and told us to go to a hyundai shop as it may be a rare computer malfunction that they haven