Ford KA why is my tracking always out

Sorry but whoever is doing your tracking is a d**k.
First thing when set up is to put the steering wheel in the straight ahead position,then I check out the turns to lock ie how many full and part turns from straight ahead to full lock L THEN R,if your say 1 and a 3/4 turn for left then a 1 and a 1/2 turn for right then I disconnect the rack and set the rack to the center and the wheel the same,then reconnect to the srubs and then track it.
If this isn't done then your rack is always going to be biased.
Not rocket science,I've set this up using string run from the rear wheel to the front rim and eyeballed it,not high tech but good enough to take it to my local real expert,his gauges cost big money,in my defense the string test is usually near to 1-3mm to factory set.

So basically what your telling me is that, the garage i went to hasnt tracked my car correctly. What do i need to do now? Because my tracking is out again and i need new tyres again

Tracking doesnt just go out you have to either have kerbed it, had suspension parts fitted or have worn joints somewhere.
take it to a recommended independant garage and not a fast fit, tracking should only need to be done once and steering wheel realigned unless any of the above apply