cranky....
I don't think you have to worry about the humira folks balking at replacing the defective pens...they make so many of them that they surely have already set the % of failure rate and know that they will get calls like yours. Multiple calls from the same person is one of three things...luck of the draw....the person is doing it wrong .....or for some reason someone is scamming them.
Reasons one and two are much more likely since Humira is not really a drug people are likely to try and sell or profit from. Not like a pain killer or other narcotic. You sound like you know what you are doing , so reason #2 is not it and they would discover this just by asking you a few questions. That leaves only option #1...
You may also want to call your pharmacy and let them handle the issue for you. Tell them the problem, ask for a replacement and let them handle it.
I have been taking two shots every other week for just over a year now (using the pen) and have only had a leak once...it was just a drop of two....and it was in my thigh.
Good luck