NTB National Tire & Battery

I took my car into NTB to get my Coil Packs replaced. Once they did the work, the car starting weird. I took the car back the next day and they told me the mechanic was off and to come back the next day so I did. The next day, I found out the mechanic was fired. Then for the next few weeks, as I kept coming back, the staff was fired and replaced. So they keep telling me I need work done because it'll fix the misfire issue coming from the Spark plug section of my car. So I get the work done. Finally, after months of going there over and over, my friend from GM looks at the car and says whatever work they initially did was the cause of the misfire and that it's going to start making the catalytic converter to go bad. So I email the store customer service and their General Manager calls me and says I'm an idiot and a moron and I know nothing. So a month after that, the store finally changes out the coil packs and spark plugs to try and fix it. Still bad. I try for 3 more months and they finally tell me to take it to a certified GM dealer to get diagnostics done and bring the paperwork back and they will do an insurance claim. I do and did. They find they broke off the spark plug in the car and then when they replaced them, they put a spark plug on the broken piece which caused the catalytic converter to go bad. So for a month, the store manager avoids me after saying he will put the claim in. Car engine catches on Fire a month after he says it will be handled. I get denied because "it wasn't the parts fault" and they manager lied and said he had no idea. They tell me it's my fault for not paying for more work done even though they said if I did, they wouldn't put a claim in and pay me back. So it went all the way to corporate and they told me they were going to stand behind the insurance company because the parts were good even though it was the labor.