A knock at the door in the middle of the night. The owner asks who it is, and a semi-drunk voice from behind the door asks back: "Did you call a plumber at any time convenient for him?" Maybe the translation isn't funny, but it should give you the general idea.
This is what we had a couple days ago. We had problems with electricity - it would behave erratically and would shut off for longer periods of time. I called the utility (the Spanish Union Fenosa) and they said they would send someone THE NEXT DAY. My last question was to confirm that they would come during the day (I was calling after 9 pm). Imagine how surprised I was when I heard the door bell after midnight a few hours later! They came and fixed the problem very quickly. Now, I am puzzled: did I have to complain that they came at that time, or should I just be thankful that they came and fixed the problem?
Apparently, it's not the first time they act like this. When our friends had some problems with electricity they were told to wait till the next day. No one showed up so they had an independent electrician fix the problem. The Union Fenosa guys came during the night after the problem had been fixed!