My 2018 Toyota Corolla has a broken camshaft despite being well serviced

The Corolla of this vintage has a fine reputation as a vehicle unlikely to fail in such a spectacular way. Assuming, as you say, the servicing has been by the book and the car has not been abused, used to tow massive loads, or operated as a rally car, then the suspicion is that the crankshaft of this particular example may have contained a casting or material fault from day one. This wouldn’t be visible to the people who assembled the engine, but could lead to such a failure after a period of time.

I’d be inclined to talk to Toyota Australia’s customer service department to see if there’s any financial or mechanical help on offer to repair your vehicle. Even though your vehicle is out of warranty, you might find Toyota will be as horrified as you at such a major failure at such low kilometres and will do something about it. Assuming that a manufacturing flaw is, indeed, the cause of the failure.

If you don’t get anywhere but wish to pursue it, an independent examination by an appropriate engineer might be able to pin-point the cause of the failure, at which point you might have another bargaining chip. Certainly a broken crankshaft at 62,000km is neither normal nor acceptable.