I have left no tip twice, once at WDW and the other at an Applebees.
At Applebees we went at about 7pm on a weekday evening. The service was really slow, she did not even refill our drinks when we actually asked(twice). When she brought out the food, it was cold because it sat so long, not sure where she was the entire time as the resturant had people at about 5 tables. She also did not stop to see how our meal was. When she brought the check, she said I hope you didn't want desert because I already totaled the bill. I paid and then as she walked away from the table I told her I needed change, she gave me a dirty look. No tip for her!
At WDW it was at Mama Melroses. We had ADR's and waited about 5mins to be seated. The waiter did not come to take a drink order for about 20 mins. Then the drinks were approx 10 mins later. When he took our app order he was very rude saying "sure you will" when ever one of us ordered an item. About 15 mins latter he came back for our entre order. All 3 of us ordered and after each one he said again "sure you will" (It took approx 30 mins for us to get our food).My meal was great, but my son's steak was basically raw and he ordered well done, my wife's meal had no taste to it. When the waiter came back we expressed our concerns and his reply was "what do you expect, you are on the Dinning Plan" I asked to speak to a manager and he told me "no" He took our desert order and brought that back in about 5 mins(that was really quick) I think he wanted to get rid of us at that point. When he brought the bill he actually stated "you can leave any extra tip you want with the slip after you have signed it". On the way out I spoke with a manager about the poor service and what was said about being on the Dinning plan and also what I was told when I asked for a manger. The manager actually looked horrified by the comments that the waiter said. He told me he would have the tip removed from the sale and would speak with the waiter and most likely send him for retraining.