I appreciate you taking the time letting us know about this server issue you have, @ThangTran.
Not getting the help you needed from our support can be really troublesome and time consuming. It is our main goal to help you with whatever issues you have while using our services.
If the troubleshooting shared on this page didn't work, we always recommend contacting our Technical Support. This is because, only our online reps can provide more troubleshooting steps and report the problem to our engineers when needed. I know you already called them several times. We want to inform you that you can always request for a supervisor on set of the call if you have complaints and get immediate help with this technical issue, without going through Tier 1 or Tier 2 support.
When contacting our support, it is best to always ask for a case number. This is a unique ID created by our representative for documentation purposes. Using that case ID, any agent who will receive your call will be able to pull up your contact history, including the name of the last person you've talked to. Also, all our call and chat channels are recorded, so they can look up your interaction easily in case you want to report your contact experience.
I'll be right here if you have other things to ask about this topic or need other help with the program. Also, please update this thread on how your call went. I want to make sure this is taken care of for you.