Cannon R-7 and R-6

I bought the Cannon R-7 for the speed of the camera. I cover a lot of events, Ren. Fest, where I want the speed of the camera. A few months, after I bought the R-7 I was at a Ren. fest shooting. I started having error messages, the camera started to lock up. The view finder would go black. I received Error 20 messages and other messages where i had to pull the battery out and reset the camera. It became annoying. I had my back up R-5 with me. A few months latter I was at a big fashion show. The event was outdoors, low light. The R-7 started to act up again. Same issues. I had to tell people that I was having camera issues, once again, I switched to the R-5. I took it into the camera shop. They sent the camera into Cannon to get it fixed. Over this past weekend, I was at a heavy shooting event. The R-7 locked up on me, again, Error 20. It is now going back to Cannon to be looked at again.

I have had issues with the R-6 as well. Fashion shows, heavy shooting, the camera will not track the models. It has a hard time trying to focus, it will go in, out, it will over expose photos, it has a hard time with exposure. I have had to switch to the R-5 or my D90, which, does a great job, but the speed is not there.

When I bought these cameras I thought I was getting great, high end cameras. Did Cannon put out the cameras, knew the issues, but put the cameras out anyhow?