Try removing the channel from the Roku home screen by navigating to the channel tile, pressing the * key on your remote and choosing 'Remove channel'. Then restart your device from Settings>System>System restart. Once your player starts up again, add the channel back once more.
I'm having the same problem. I spent my entire Saturday dealing with Roku support and WWE Network support. Roku says it's paid. WWE says it's been deactivated. Roku took the money, so Roku needs to fix the problem or refund the money. It's that simple. No more passing the buck. Roku needs to take responsibility and make it right.