How can I permanently disable USB debugging mode?
This happens to myself, you would have to turn the device off several times whilst your USB is connected and just wait for it to stay turned off, once its turned off it will not turn back on unless upon reconnection. It's a very old phone and is not a good phone so this is why it's like this. I wish there was a better resolution myself but after browsing the internet for around an hour I figured I'd help a somebody else and let them know what I know.

Thanks.