I can see protected tweets only up to 8th February 2015.Why can't I see the older protected posts???

Problem
Updated 2 months ago

Hello. I am subscribed member of a twitter channel. The owner made his tweets protected since the last week. I can see his recent protected posts, so no problems here. But since the time an owner made his tweets protected, I can't access his older posts, older that 8th of February 2015. And his posts go back for about 2 years probably. My question is: how to see his older posts ??? Please help me. It's very important to me. My twitter is : https://twitter.com/siege_engines Please help, guys Thanks