I also work tech support, for Cisco phone systems. I know how support goes.
Even for simple follow up questions it takes them 10 days. Every single email is around 10 days.
Whether you are creating a new ticket or replying to a question. They will not look at it for another 10 days.
So every time they ask some stupid question like "have you tried a higher bit rate?" - they buy themselves another 10 days to not have to deal with your question.
Every kind of tech support person is familiar with jerking people around. I've done it: "Can you reinstall that and let me know how it goes?" (who knows, it may actually work!)
Presto, you just bought yourself a few hours to a few days!
If a customer is replying to a question you ask, the delay to continue working on it should only be as long as the customer takes to reply with valid information. You should not be put back to the end of the queue with all the new tickets.
Cyberlink has asked me 3 "quite basic" follow up questions that show they haven't put any time into troubleshooting yet (because apparently they need more information like have I increased bitrate) and it has taken an entire month.