Problems with youtube and Vevo music videos apps

Hi, I had a question about the youtube and Vevo apps. I've been having problems with them for several months, and they're not getting any better. For instance, the youtube app, the one that you can watch on your tv, it used to play fine, but let's say I watch a four or five-minute video, no matter who the artist is or how good/bad the quality is, towards the end it will start to freeze/skip at the same place, towards the end. Even if I watch a clip that's an hour or longer, the last minute/30 seconds will start to freeze & skip. Is anyone else having this problem?  I've tried resetting my box, deleting the browser history but to no avail. I've even tried calling xfinity, but it's like pulling teeth to get anyone to answer the phone. The recording suggests refreshing the system, but I've already done that multiple times. When I finally get someone on the line, nothing they suggest works. They also offer to call you back, but never do that. Also, I'm having problems with the Vevo music videos app. I will pick an artist, no matter who the artist is, and will try to play one or some of the videos for that artist on the app. However, most of the videos won't play. You click on the video, and it won't play, or you'll hear the video but no picture. This has been going on for months. The last time I did a chat they told me something along the lines of they will get someone to refresh or fix the problem, but it never happens. Also, they offer a callback, yet no one calls me back. I'm tired of this poor service I've been getting from xfinity. When I did the chat, they did offer to give me a new box, but we have two boxes, and both boxes have the youtube & Vevo problems. We recently tried to call xfinity after we had more problems with the youtube app, and they hung up on us. We pay almost 200 dollars a month for cable, and we get this poor treatment? Any advice/help would be appreciated.