How long do you have to store something before it legally becomes yours? (Best Buy)?

We ordered new appliances from Best Buy. When they came they all dents in them. Best Buy offered us new ones but said we could use the first ones they sent until the new ones arrived. When they came hubby was at work therefore I didn't know how to uninstall the dishwasher. They said they would set up another date to come back for it. They was supposed to come back about 2 months ago to fix a problem with our fridge and pick up the dishwasher. They never showed. We figured out the fridge problem and got it fixed ourselves but they still haven't came for the dishwasher. I have called numerous times and left messages, emailed, ect nobody ever calls me back! We have stored this thing for 3 months now and I am getting sick of holding it since we don't have the room and I am like a clutter freak (HATE CLUTTER!!) I want it gone but Best Buy seriously won't come pick it up. How long do I have to store this thing and how many times do I have to contact them about a pick up date before it is legally mine? I'm not trying to keep it but they won't come for it! And seeing how I am not that happy with Best Buy selling it and getting some money back won't be a problem for me! Thoughts? Suggestions? Driving there is not an option we only have a car and can't fit it in the car and why should I use my gas at 4 dollars a gallon when all of this is their mistake!! What should I do?