IMHO, on a normal day in tech support, a response should occur within a couple hours from any casino which boasts 24/7 support.
On a day the servers go down, it can go longer...
I personally give them 24 hours before I start getting annoyed. Most of the casinos I have contacted for tech support have replied within an hour or two, though.
About intelligent responses, though, that's another story. Why does it seem they presume anybody asking for tech support to be a complete moron? Not just casino tech support - but all tech support. I can't count the times the response I've received doesn't seem to be at all related to the issue I presented!
And then you have the ones with attitude. You know the ones I'm talking about. These guys keep telling you the sky is pink when you can clearly see, and keep telling them, that the sky is blue. But they're sure you don't understand what blue really looks like. By the time you get one of these "know it alls" to hear what issue you're having, you're ready to call the local psychiatric hospital and check in for a much needed rest.
If you are obsessive-compulsive:
Please press 1 repeatedly.
If you are co-dependant:
Please ask someone to press 2.
If you have multiple personalities:
Please press 3, 4, 5, and 6.
If you are paranoid-delusional:
We know who you are and what you want. Just stay on the line so we can trace your call.
If you are schizophrenic:
Listen carefully, a little voice will tell you which number to press.
If you are a manic depressive:
It doesn't matter which number you press, no one will answer.