2001 Other Toyota Models struts

I have toyota prius. There is some problem with rack and pinion and I went to dealership to fix rack and pinion in the month of september 07. I did not notice that a noise from front passenger side is coming.
yesterday I went to fix my breake to auto body shop and mechanic noticed that there is some noise coming from front passenger side and he informed me the same thing. He also told me that noise is coming from sturts.(Front passenger side)
today I went to dearship and ask them that there is some noise coming from front side. They told me to drop car and they will let me know.
they called me and told that my front passenger side struts has to be replace.
my question is, they have replace rack and pinion and during the job work they damaged the sturts. But they are not accepting their fault and they told me that my car has 116000 miles and that is a problem.
so what do you think, did they damaged my sturts during replacement of rack and pinion?
how am I going to prove that they have damaged the sturts.
let me know.
thanks
ashwin