I think I fit this description (wavvy lines taking us back to Sunday night):
I went to Chiquitos in Nottingham (first time), got a seat immediately and had my drinks order taken immediately. Was impressed, but woefully this wouldn't last!
After 5 mins the drinks are still sitting on the bar top, so I go over and ask if they are ours. You know I'm a pretty boy and I don't want it being spiked

. The girl at the bar checks the receipt next to them and yes, they are for our table. She offers to take them over, but I don't see the point as I'm right there and may as well take the drinks with me on the walk back. Kinda phased that they were left there and not bought over earlier, but meh.
Next someone comes over to take our order. We were reading Deadpool comics earlier; obviously we all order chimichangas. Two shredded pork and one chicken. The order was taken and the food arrived pretty quickly so again I was happy. However, halfway into my first chimichanga I turned to my friend and said 'this is not chicken'.
'This ain't pork' he replied. The kitchen had got the little name flags the wrong way around. I was quite frustrated about this as many of my friends can't eat pork: it was fortunate it happened to me and not one of them! So another bad stroke.
It's getting late now and we're still slowly plugging away at our food. The waiter comes over (I guess they want to close down soon) whilst we're having a break (chatting instead of eating). He asks if we are done. "mmmmm... no" I reply, yet a hand comes over and picks up my plate. "Errr... Oi!" I stammer and yell. They might be filling, but dammit I wanna finish my delicious food! Third strike.
So we finish our food, ask for the bill and for the money to be rounded up and split 3 ways on our cards. We pay up and leave. It's too late and we're too British to complain. The food was delicious, but the service was awful. I certainly won't be a regular visitor, indeed will probably never go back. Especially if that waiter is there, haha! I'm disgusted that the kitchen mixed up pork and chicken. That's a pretty grave error.
Anecdote complete and getting to the crux: the idea of the silent customer/silent killer is definately of merit. If I have bad service I'm the kind to pay up, leave quietly and be much more reluctant about coming back. This applies whether I've had bad service (as per my anecdote) or I feel staff are too snide or passive/aggresive about my 'dollar'. If you don't think they're worth the bother/money anymore just don't go back and leave them to rot. That said you have to give them a few chances; everyone/thing sometimes has off days!