I've already fielded this question multiple times on the forums (Use the search feature
).
The reason a Support Centre isn't made on the login server is because if for some reason someone can't even log into the client (Account locked out, globally banned, servers lagging badly, etc etc), how are they supposed to contact the Support Centre? So internal Support Centre is a no-go.
As for an external Support Centre, tons of effort was put into finding new software. Tig for one spent days upon weeks looking for alternatives, but Stefan shot them all down even if they were good. I could only assume reasons for this, but I'll never know for sure why he won't accept other software.