tires and rotations

Purchased 4 new Yokoama tires last year with a milage warranty. To be rotated for free every 8K miles. One rotation session was a peelout test for my car...worker churped the tires and sped out of the garage when finished (right in front of me). Then the last rotation led to a huge shimmey in the front, took it right back fearing something was wrong, they told me the rim was bent and that it would cost hundreds and hundreds to get a new one. I went to another tire dealer for a second opinion...no bent rim and my Yokohamas are all worn out. Crap tires and service.