When is enough enough?

Back in the Spring I began using a shared facility at a neighboring University to prepare some samples for my research. As the summer hit the number of users at the facility increased dramatically and it became more difficult to get time on the tools and with the staff members. Being fortunate enough to live close to this facility, as many users are not, I made every effort to be flexible regarding my use of tool and staff time. I really pushed myself to be diligent about timeliness (I'm usually late for everything), and I strove to be forgiving when staff arrived late for training appointments with me because I understood how very busy the summer season is and appreciated their time.

Now, each new user at the facility is assigned a "host," who performs most of the new user's training. My host and I had a really good working relationship going, until the summer hit and my host began constantly running late. I waited on him for as long as 30 minutes on several occasions, and was eventually completely stood up by him. I let this stand up slide because, again, I know how busy the summer is and because I've learned that you can get farther with kindness than with confrontation. But then it happened again, and I got ticked. As a grad student I'm used to being walked over a bit, but this seemed ridiculous. My host claimed he had been pulled into an impromptu meeting, but I contend that he could have called. There are pager phones EVERYWHERE in the facility. So, I sent him an email and suggested we take a "break," and that I return when the busy summer season was over. I was pretty sure I had ticked him off in return, because he didn't immediately return my emails when I contacted him a couple weeks ago to get started up again. When he finally got back to me, though, and we had our first appointment back at the facility, he was on time, we chatted amicably while at our task, and I walked away feeling good.

Then today happened. Despite really needing to return to my own University today (2 hours away), I arranged an appointment this morning at the facility because I knew it was a convenient time for my host, and I wanted the task out of the way. When I showed up at the facility this morning there were 4 people there. Four. And guess how late my host was to our appointment? 30 minutes! Really?! What could he possibly have been doing? I honestly don't know what I am going to do at this point. Well, sadly, I do. I'm going to hang in there and deal with it because I am literally days away from finishing. But how do I prevent this type of situation in the future? I worry that if I'm too stern I'll upset the person I'm working with and ruin the working relationship. But is the alternative really to be walked all over?