Can shaft failure again within 45000 miles Skoda scout year 2008

Hello all

Engine bmm with 165000 miles cam shaft failure at 122000 miles. I change oil and filter every 5000 to 6000 miles. VW 507 oil used along with OEM filter. The mechanic thinks that the shaft that was installed was of poor quality or the replacement shaft was not properly adjusted on installation.

Thoughts on why this shaft failed after circa 45000 miles given the attention to oil changes. Question becomes fix the car or change. I like the car a lot. But this is very disappointing. I have a 2008 ford Mondeo and it never gives bother.

Tsm