If they no longer want
YOUR traffic you can either:
1. Find a sponsor that features the same model/niche and refer said traffic to them - replacing videos/banners.
2. Find a competitor similar model/niche and refer said traffic to them - replacing videos/banners.
3. Really Pissed? Replace videos with your own videos discouraging people from joining said sponsor.
In all cases keep titles/descriptions so you don't loose YOUR traffic!.
Under no circumstances take the complete page down as you'll just be handing all your hard work and traffic to them on a plate for free.
ALSO NAME THE SPONSOR SO OTHER AFFILIATES DON'T SUFFER THE SAME MISFORTUNE.