Timing chain failure 520D 2011 Model

[Michael015]

Very disappointed to highlight the failure today of the timing chain in my BMW 2011 520d at very low revs. The mileage on the car is 67,000 miles and it has been serviced by BMW dealerships all through with the exception of one non BMW dealership where I bought the car a year ago. How prevalent is it for timing chain failures these days on the modern 3 or 5 series models. I am aware anecdotally of premature failure of timing chains associated with the circa 2008 approx models but was told that this unreliability problem had been solved in the more recent Diesel engines.  It is ironic that after 40 years of high mileage driving all car models (mostly diesel) when I changed to the so called "Ultimate Driving Machine) in near retirement the car has turned out to be the most unreliable. 

I would appreciated feedback from anyone who has experienced similar premature but out of warranty timing chain failures and what support was provided by BMW cost wise given this continuing engineering design fault.

Thank you.