Device administrator issue with stolen phone

my husbands phone was stolen last week. I got onto the computer and tried to use the wipe and lock app. neither would work. said I had to be a device administrator, tried texting the commands aswell. still same result. when he added the Norton app to his phone he turned the device administrator on in the app settings, it is turned on with my phone aswell. How will I be able to send the command if it happens again and it will work? shouldn't being on my account on the web page show I am the device administrator? just wondering if we didn't do something correctly when setting it up... if I cant use the features, what is the point of the app? I called customer service and the guy I spoke with was very rude and emailed me a "how to" on the app. but it still did not answer my question. both of our phones are androids if that makes a difference