a. if you are having issues with exposure, I'd suspect the body not the lenses. The odds of two lenses going bad in that way are very, very low.
b. Call Canon support, there may be a deeper reset with firmware upgrade
c. Explore cost of repair with service center. Most likely much cheaper than replacing the camera body.
I can't recommend any particular Canon as I own a Nikon, but dpreview.com is my go-to site for reviews.