I've heard from Support Staff that it's impossible for them to man the live chat 24/7 so there may not be any Support Members available to you all the time. If you still need help you may ask here or Email them through [email protected]
I do apologise that you feel that no agents have been on for weeks. I can personally attest that they have been on at certain times, however with regards to the support team they do have loads of things to do from reviewing channels to answering support questions posed to them as such it could be that they just aren't active when you are on.