My verizon note 3 will not register on a network?

I have a galaxy note 3 verizon that was flashed to straight talk, I put it back to factory settings, to be able to use it on verizon pre-paid verizon, told me that it could not be used because it was running on another carriers towers, I am not sure what to do with the phone. I want to use it now with straight talk with a verizon sim. but couldn't get that to work either.

Can this phone be fixed.????

thanks