Sewer Arena Exploit

I thought Blizzard looked into this and was suppose to have fixed it.

Last week, just about every warlock team we played set up their portals in the tubes at the beginning of the game. Whenever the lock got into trouble, he simply ported up into the tube out of harm's way. I remember hearing somewhere that this was an ability that wasnt allowed anymore. Pretty cheap. He ports away while the dots are still ticking on both my teammate and I, and we cannot do anything about it. Then jumps off the pipe and lays a couple fears and refreshes dots before porting back up into the stupid pipe.

WTF!!??