Report to Gakin the Darkbinder in the Mage Quarter of Stormwind.
<name>! Didn't expect to see you around these parts, but I was instructed to keep an eye out for you.
It's past time you got some more training, so you should stop in to see Gakin the next time you're in Stormwind. He'll be waiting for you.
About time you showed up. Though, perhaps I should have sent someone more capable than Remen to find you.
You've gone too long without training, and a warlock without training isn't like to keep his head on his shoulders for long.