Koops poor service

Koops the only good work they do is to service new cars... I took my hyundai accent 2012 for service on the 10th April 2019. I usually bring my own parts but this time I only took my oil and oil filter . They used their own spark plugs and air filter. It was 180 000km service. After driving for about 6800km my car was miss firing.. I thought it could be a coil pack. I checked all my coil packs all were firing. The I changed their so calked platinum spark plug that should last a minimum 40 000km. Then my car ran smoothly. I CALLED them they said they would call back to refund me for the spark plug and give them the faulty ones back. But never cane back.. Called again the next day still nothing. I trusted this people but I see they have too may customers to care about one. Soo no more me and koops... I also realized that on that serviced they said they checked everything but it was a lie my brakes were not checked. And they did not even call for the special tool to remove the wheels I realized 2 days later that It was not in the car... Talk about integrity.. Trusting them with the safety of my cars....