Ignore Feature?

I keep getting put in games back to back with people I have muted and ignored. Is there a reason for this? I thought once you reported and muted them you shouldn't be put back in games with them let alone ON THE SAME TEAM. I've gone on tilt so hard and raged so hard because of three of these people, I'm legit going to get banned. But is this working as intended or is it bugged? Thanks in advance.