Last year I bought a ribbed car in Carmot and they...

Last year I bought a ribbed car in Carmot and they promised me a free regular service to change the filter oil and brake oil, I made an appointment and came to the service. When I handed the car over to the workshop they first complicated about who promised me free service even though I had written proof on the purchase offer, when we settled that the mechanic took the car to the workshop and I was not allowed to see what it was doing. I hope he at least replaced the oil in my engine because the oil filter is not like either the brake fluid or the air filter. I was convinced of that a couple of days ago when I attended the oil change when we took out the filter cartridge it was all deformed due to clogging which could not happen in 9000 km traveled. Like the oil in the brakes it was not good and the air filter was all black and clogged.
So after such services we wonder why the car breaks down?!.