Just because a company claims to be kosher, does not mean that they are kosher. They must provide proof of a certificate from a kosher supervisory organization (and they are not created equal). Companies which are certified kosher have a kosher supervisor who "pops in" for surprise inspections. When companies are selling you food as "kosher", but are not transparent, they cannot be trusted.
I have attached a Beginner's Introduction to Kosher in Jails & Prisons. Even if you feel that you know it all already, please take a moment from your busy schedule to take a look at it.
Feel free to respond publicly or to me directly.