Brandale510

My car recently started doing this after i bought new tires. I bought my tires at sears and since it was under warranty i brought it over there. They thought it just needed to be balanced and rotated but It still had the same problem and i brought it back. They told me their machine wasnt working properly that night so they rebalanced everything for me again. The third time they made sure they checked everything even the struts but still were not able to help me out. What other places would i be able to go to to have that checked out and fixed?