Something that gets bandied around in the larger enterprise base is something called an SLA. It's a service level agreement. Another variation of that might be a service level objective. And whether you use those terms or not, there are a couple of key questions that you should be asking your provider.
In this case, an IT provider, since that's what I am, that you should be asking your IT provider. Here's a couple of those questions.
How long should I expect to wait for you to get back to me? A very simple question. It's a response time question, if you're a law firm who's billing at $600 an hour and the response is "I'll get back to you later on today" that's a very expensive response time a response time. On the other hand that says "we guarantee a response time of 15 minutes or less." Is something that you can put your hands down and go, okay, I can, I can understand what that is. And if it's not, what do we do about it?