What a terrible place I paid 650.00 for a tune up ...

What a terrible place I paid 650.00 for a tune up and 150.00$ for a diagnostic then about a month later it started acting the way it did before now I told the guy (Eric) to keep the old parts and he didn't so I go up there they run a idle check and say that's normal so a week later the check engine light came on i called told him I said it could be a failed plug I need that plug checked he denied it and wanted me to pay another 150$ for a diagnostic test complete rip off oh and the woman manger completely disrespectful I will never go to this place again I'm serious straight unacceptable service and disrespectful people!!!!!!!!!!!