Hopefully i can help..
It is quite unusal to see wear at such mileage depending on the extent at which the wear or play is on those ends - for them to be replaced that soon..of course other factors such as road conditions/pot holes and such dont help either,and we see that alot on most 4x4's/cars..the problem with it being steering component means any play in the balljoint as per track rod ends would upset the steering/tracking some what and thus knock on effect with tyre wear..so sadly they have to be replaced to ensure the steering/tracking isnt effected...
Thank you Robert and I understand that road condition would be a factor. I have asked for the worn parts to be returned to me so that I can have them independently checked.
Normally on these it would be the ball socket on the balljoint itself,if there a torn rubber boot around the joint the this can cause the grease to leak out ..obviously they would class that as a wear and tear item..but they can not be reconditioned but replaced to solve that issue..also to add any new balljoints that are fitted can be alot stronger than the original fitment..... However if you can rate my responce/answer above that would most appreciated.regards Robert