The one thing that drives me around the bend (like I want to choke the $#@& out of the support person), is when I get a canned response instead of an answer to my question. That actually makes me mad! (Canned responses or vague responses are so very obvious).
For example, the server was down a few days ago, and I emailed support. Their response was:
"I have checked your servers, seems everything works fine.
Please confirm.
Please let us know if you have any further questions."
The server was down (as others were aware of it). If something was done to fix it, then support should say so.
A better response (I think) could have been something like:
"It was down but, we have fixed the issue, the problem was xxx."
Or...
"xxx caused the issue and we fixed it. To prevent this happening again you can xxx".
If I'm told how to fix something (or what caused an issue), this can take some load off support in the long run.
It's the vague and canned responses that illicit aggression.