Welcome to the forums.
I am sorry that you are frustrated. I am not sure why you wouldn't be able to use an Android phone on the network you want... you may be best speaking to Straight Talk to see why the phones wouldn't work. As far as I am aware, if the network has coverage in your area, then you should be able to use any phone on that network.
As I said, the people who would be able to tell you why you can't use an Android device on their network would be Straight Talk themselves.