Poor workmanship

April 13, 2015 I replaced 2 front tyres with new Yokohama tyres - done wheel alignment and balancing. June 12 2015 done the 2 rear tyres - done balancing. In a month there was a judder driving at a speed above 100 Km/ph. I took (June 25, 2015) the car back to TWT to check what the problem was. It was a balancing issue - balancing was redone at no cost. In another month the problem was back - I did not take the car back again for them to check. However, when doing brake maintenance on the Front Left wheel- taking the wheel off. Two nuts on the wheel was stiff - even after they were slackened. On closer inspection I realised what the problem was. One nut was not the original correct nut - it was replaced by TWT with another nut (the thread was not the same as the original nut). TWT forced the wrong nut on the stud to rethread the stud. Then app**** grease on the other stud. The replaced nut was then put on the other greased undamaged stud. Another undamaged original nut was then put on the rethreaded stud. Now 2 studs and nuts were damaged. The damaged nuts can only be used on the damaged studs - using them on the other undamaged studs, would also damage them.