Was part of a project where I needed about a day's input from another team so I could finish my tasks, but their guy on the project had been grabbed for something else. I started emailing him and his team lead (and .cc-ing my manager and the project manager) about 6 weeks before the pilot was due to start, saying I either needed their resource back, or somone else asap. I did this at least twice a week, as well as speaking to the team lead whenever I saw him, until a fortnight before the pilot, when I started doing it daily.
Three days before the pilot, I was working away and got a call from my manager, the project manager, the other team lead, and a couple of the others involved in the pilot, angrily asking why I hadn't delivered yet. I politely pointed-out that I'd been asking/emailing for 6 weeks without getting anywhere so they needed for somewhere else to point the finger. I also forwarded them all of those emails whilst we were "discussing it". They allocated someone to work on it that day, and I did what I needed remotely the following day. Sorted.
When my manager called me 15 minutes later to apologise "for putting me on the spot, but they'd come to his office on the warpath", I told him in no uncertain terms that he should be eternally thankful I was 250 miles away, otherwise I'd be taking him outside and punching him in the fucking mouth - career-ending or not - and that went for any future occasions also. Never had that problem again...