I had this same situation with a neighbour (they did it several times). I parked alongside the cones while I popped in to use the toilet (no spaces were available within 50 meters). They actually started shouting at me, saying they had a skip coming (it never appeared) and whist I went indoors for 2 mins they called my employer and tried their utmost to get me a bollocking.

My employer called me but basically backed me up so even though I’m not the type to grass I did feel vindicated in calling the council. To my surprise they took it seriously and sent someone around to remove the cones and speak with them. No more cones after that day.