"can you hear me mother?"
This isn't as epic as previous stories here but it tickled me
I work in medical devices governance for a hospital trust and had arranged for our IT department to fit an I/O card into a PC for a thermometer calibrator. I could have done it myself but it wasn't my PC so I thought do it right, and get them to install it. A little later I get a call from the ward sister to say that someone had called out but said the card didn't fit. Having seen the card and PC myself I knew immediately what the problem was, so I called the helpdesk.
"Hi, I'm calling about a request to get an I/O card fitted"
"Yeah, I called out but the card doesn't fit"
"It's a low-profile machine, did you try turning it sideways?"
I get a grumpy "no, I'll call over" in response
and then as I wait for him to tell me when he'd be out, the next thing I hear from the phone is
"Eugene Doherty, who the fuck is he anyway?"
"...Telling me how to do my job..."
He had obviously cut off my side of the call but not his. There then followed several more minutes of ranting to his office colleagues about me and then his supervisor who'd had the temerity to tell him to go to another building a short distance away to fit new hard drives, "...and it's raining outside!"
After trying to interrupt his tirade several times, I hung up as it was clear he couldn't hear me, though I could clearly hear him.
I subsequently emailed his boss, in amusement rather than anger as he hadn't realised he was addressing me, but advising that they teach him how to hang up before slagging off the caller