Frank's A42BLEUsed Cars

On 2-11-2011 I purchased a car from Frank's A42BLE Used Cars, and after feeling rushed and pressured to buy the car, he neglected to tell me or fix the radiator as it was being held in with wire. My mechanic found it when he did an oil change to the car two weeks later. I called Frank's and told him about the problem and he refused to fix it and said it wasn't his problem. But if he knew about it before he sold it he would of fixed it. It should of been fixed by him regardless as if the wire gave out and the radiator fell out it definitely would of caused an accident. I have a 5 year-old daughter who rides in my car and that was not a safe car for her or I to be in. I had to have the problem fixed myself and I feel he should pay for it as I believe it falls under the lemon law.