I'm sure I'll get flak from some of you for saying this, but when this happened to me on an Aerolineas Argentinas flight (MAD-BUE) in C class, after I'd asked them 3 times and had the service light on for 30 minutes, I put the stuff onto the floor in the aisle. When they finally did come to clear it, I had the pleasure of being able to be as rude to them in Spanish as they were to me, thinking I wouldn't understand.
Their only competition, if you can call it that, on the route was Iberia and Air Vomit, so hardly surprising that their service is so appalling.