Bad Lexus experience

I have a 2011 lexus RX350 SE automatic. After it ran out of maintenance plan, 90000km, I discussed it with Service Manager and we agreed that these cars have a history of longevity and would see out 250000km + without significant costly issues. On the 16/09/2021 my vehicle went into lexus for its service (Full service History) at 145****m. About a month later I experienced some issues of it not going into gear and again a few days later. It corrected its self both times. I then contacted the service manager who kindly arrived with the diagnostic machine which showed up nothing. He test drove it and then apon parking it,he experienced what I was complaining about. The car was re checked and a sample of transmission fluid of 1.5 liters sent for diagnosis. The car was returned to me with no outcome, and appeared to be alright. Then on the 27/12/2021 driving to Sodwana the car transmission failed outside Middleburg on the freeway and had to be towed back to Lexus. After a further 3.5 weeks , I now have a costly R38000 to find for an apparent torque converter bush that had seized. A major job and a further 2 week wait without a car. This does not just happen to a Toyota Premium brand, where Lexus just wash their hands of the cause. The warning signs were brought to their attention before, the breakdown. I feel that they are at fault for not paying serious attention to the warning signs. The service responsibility from Lexus has deteriorated and I am seriously thinking of avoiding buying another due to this.