Yesterday I took my two youngest kids out to play 9 at one of the munis, and we got stuck behind a foursome that had zero clue. Multiple shots from each (to be fair, I'd probably take a couple extra hacks if I was only topping it 6 yards at a time), animated arguments amongst each other, extra time on the the greens, and just generally moving slow. My 7 year old and 12 year old playing partners caught them on the second hole, and we waited on every shot. I took extra time on the greens to repair what I assume were their freshly unrepaired ball marks, and still ended up waiting for them on the next tee boxes.
On the par 5 sixth, after what I assumed was a long enough wait (after checking and seeing their carts left towards the green), I smoked my 3W towards the front edge of the green. When I cleared the hill to see where my shot landed, I saw one of the foursome get out of his cart, pick up my ball from just short of the green, drop it in his bag, then proceed to line up his putt. I drove down to the group and apologized for hitting into their group as it was a blind shot, and they all looked at me like they had no clue what I was talking about. They asked me what ball I was playing, and I pulled one out of my pocket and showed them my marking. I received a blunt "Nope, never saw it" before they all pulled away.
I can't 100% say that it was my ball as I didn't see it hit the ground, but I'm 99.999% certain that it was, given the line and distance. I spent 4-5 minutes looking for my ball with my kids before dropping near the spot I saw the ball. I've never had anyone pick up my ball in front of me and then deny it when confronted, and to be honest I was pretty pissed off about it. I had to take their word for it and move on, but has this happened to anyone else before? What did you do about it? 4i stinger on the next hole?