Bad Product

Afternoon. I have a Jurgens Expo 2014. I use the EXPO 2 time a year. After Lockdown i went on holiday. I hit a pothole on the way there and the axle collapsed. the report from AL-KO stated is was due to ware and tare. My caravan is brand new. has not done 8000 km. How is it possible for the axle to be worn out?