Xfinity Parental Controls DO NOT WORK AT ALL!!!

I am super disappointed with Comcast's behavior when it comes to parental controls. I assign devices and turn on parental controls but yet you can still search explicit words and get all kinds of graphic images and videos and sites. NO Blocking WHAT SO EVER!! Totally lets everything through. But then again why would a content provider want to block anything? Also, I was using clean browser DNS and OpenDNS but last night Comcast you must have blocked my ability to do that because my router that uses them lost internet entirely and my pi-hole won't work either. I disabled them and used my other router and even jacked directly to my xfinity router and used Cleanbrowser in the DNS settings of my Mac and sure enough NO Internet. which means Xfinity/Comcast is poisoning my DNS and NOT allowing me to choose my own darn DNS server. WHY??!!!  I am so MAD I could scream!! Fix this immediately! I need to be able to block all the explicit junk that you think is just fine for my kids before they find it.