Good Year Tyre — Very Poor Quality of Good year Tyre

Purchase New Car Ford Eco-Sport. In which Good Year Tyre are Installed. Car run just only 3k. and its 3 tyre get defected out of 5. Defect is that all three tyre get leakage from side not lower side. and that leakage is very minor. That leakage is such slowly that air completely leak in 4-5 days. When I complaint they told that it is not Manufacturing defect. and told these are damage by some external object.
If it will be damage by some external object then air can't stay in tyre upto 4-5 days.
So Very bad Experience with Good Year. and suggest never Purchase Good year Tyre

Thanks