We were sent the wrong cable box and no one is helping us out

So we change plans since our contract ended, just to a different amount of channels. And xfinity said we will send you a new cable box. So they did and I went to return the old box at a xfinity location. There they told me that I was given the wrong box because the one I was returning (keep in my I was returning my old one) was the one I needed and I should just return the new one. They claimed that I was sent the wrong box. But whenever we connected the old box back, it was completely shut down and it wouldn't connect. And the one that they sent, we connected to see if it work.  But it says connecting for hours. I even contacted someone on the phone for xfinity customer service and said they could not help us and then hung up on us. Now we cannot watch the news like we need to during this time. Someone please help.