OxyMoron wroteI've been suffering from bad latency since i joined, about 2 months ago, 350 to 400ms regardless what time of the day or night. I just sent them an Email, what is my success rate in having them cooperate and not dodge this with insane reasoning?
Have you contacted them before by phone during those 2months?
If your issue is a constant yet stable latency at 350-400, then they consider "normal" unless you tell them that you game or any sort of task that requires low latency. Then they would probably change it for you and put you on much better latency.
As for your question on emailing them, they've never replied back to my emails but I suggest following up by calling them during a workday and making sure they're proceeding with your case.
As Samer mentioned earlier:
Then call every day and follow up until they fix it.