If your tyres have been running off track and have worn at an angle then when you get the tracking set up correctly the car will still probably pull until the tread wears down evenly again. If it's been really bad then it really takes some flat worn or new tyres to see if the tracking is now running ok.
Then there's the new tyre problem. Sometimes even new tyres will track "off". I've had two new tyres on the front (on a different car) and it pulled left so, after finding absolutely nothing wrong with the suspension or steering, checking and rechecking many times, I change the front two tyres around and it pulls right! Great! :bang:
You've got to keep an eye on your tyres regularly chaps! At least every week. They're the most important thing on your car! Waiting until the metal is showing through on one edge is chronic for your safety and your wallet
I do my own tracking by old methods and is always 100% and more reliable than that done by the tyre shops. They don't even check whether you have any wear in the suspension/ steering BEFORE they do the tracking. Pointless trying to accurately track worn components