Why is my car pulling to the left ( including steering wheel) and the front inside tires are worn ??

[Fastlife91]

In December suspension work was done by a friend on my car, this include track rod ends so obviously after these were done the wheel was well out. Got tracking done right after, however the steering wheel still pulls to the left slightly and I discovered both front tires were worn on the inside. 
I went for a free suspension test last week, revealed track rod ends were worn ( despite only being fitted few months ago) wheel bearing is bad and axial rod slight play. 
Garage said steering wheel pulls because of bad tie rod ends, but I'm confused as the car has had this pull right after the track rod ends were replaced in December and even after getting the tracking done.

Does anybody have any idea what the problem may be before I pay to get all this work re-done as I don't want to have the same issue for the third time.

Do you think it was bad parts, bad fitting, maybe he fitted other suspension parts wrong ? 


thanks

[Ryan_Tango]

I'd go with bad fitting and possibly bad parts, get the work done by a garage this time and then get tracking redone.