Plugin rotating testimonial in sidebar

I’ve tried adding three different rotating testimonial plugins for the right sidebar. None of them rotate, and simply list the testimonials one after the other. (plugins; Rotating Testimonials, Easy Testimonials, Simple Rotating Testimonial).
I have two other rotating plugins in the left and right sidebars which perhaps
could be influencing the issue; Image Rotator and Rotating Quotes.
My site is worldpeacesolutions.net
I have no skill in coding, unfortunately.
Any advice is welcome. Thanks.