CBS on Sundays

How come every Sunday whatever comes on that we watch on CBS is messed up? Right now it's The Unit and every summer it's Big Brother. They run whatever show is first too long and it makes us miss the show we want to see. Tonight I set up The Unit to tape and it didn't come on at 9. R just flipped by CBS and it's on which means it started really late and we missed it. It's getting annoying and they've done it for a couple of years at the least. Someone should complain.