Dishonesty on quality of vehicle sold

Purchased a vehicle from Integra Motors in June 2019 (last month) Now I have noticed that the car had 3 Nexen tyres and one other brand of tyre which the 1st tyre has hardly any thread. 2nd tyre had a plug put in. 3rd tyre is whopped, that even if you roll the tyre, it doesnt go straight. 4th tyre has worned inner walls. Called Integra Motors this morning at 08:30 to complain and I was told that the Manager will call me back, he was in a meeting and should be out by 11am. Its now 12:41. When I called Integra Motors, I was told that the manager is in a meeting and will only be back at 3pm. Its seems like Integra Motors is only worried about a sale and not individuals safety on the road. My question is how does a vehicle pass roadworthy in a condition like this???? Poor thread and damaged tyres can cause accidents!!!!!!