Not sure where you stand legally, but personally, if the appliances are no good to you, i would either give them away (friends / family ) or i would ring a one of these second hand furniture shops, they will come and take them off your hands and probably throw in �50 approx for the lot. That will save you having to pay someone to tip it. As you've exchanged contracts and completed the sale, i would say that they are now technically storing their stuff on your property... up to you what you do with it i'd say. I certainly wouldn't waste any more money paying solicitors fees trying to get them to follow it up. Good luck