Hi John,
I completely understand your frustration - it's no fun waiting for someone else to deem your situation to be a high priority for them, especially since they already promised you something. That said, you are really putting yourself in a bad spot if you want to rectify the situation. My first suggestion is to find out if there are any reasons why they may not be moving forward, including looking inward - you are saying yourself that you are not taking your job seriously because you are upset, so it is very possible that she is rethinking things because of your actions. It's been a month and a half since the time they said they would give you the promotion, and there is no excuse for them not moving one direction or another on that, but at the same time, I feel a month and a half is not so long that mentally checking out of the job wouldn't raise some red flags.
Overall, if I were in your shoes, I would be asking these questions:
- Am I giving them any reason not to move forward?
- Is business abnormally busy to cause my manager to not be able to move forward with this?
- Does my manager understand how the delay is causing me frustration?
- Are there any other reasons why the company may need to delay filling the role?
It's very possible that your manager is simply overwhelmed with other things, and at the same time, doesn't realize what stress this is putting on you. The reaction to that scenario is going to be much different than if they are actively trying to jerk you around.
Again, if I were you, I would be proactive and ask her to put it on her calendar at a later date, rather than calling every day and hoping she happens to be available. I would also absolutely show that I am right for the job - if you have checked out, then you won't have a leg to stand on. The more competent you are, the less than are willing to lose you, which gives you more leverage.
Ultimately, however, whatever steps you take really are a function of the answers to the question above.