What to do?

[Sulli]

G'day all,
In August I sold a single car garage on ebay with the winning bidder to dismantle it and remove. The person has paid for the garage and started to dismantle it on a sunday.
That was the last we saw of them. I had to dismantle the garage myself and it is still sitting in my front yard which makes my property look like a scrap yard, All this took place 4 months ago.
I have made alot of phone calls, sent heaps of emails with little or no response. The last contact I had from this person was on the 11th of December and the assured me it would be gone by the 12th December.

Does anyone have any idea on where i stand legally? The garage doesn't belong to me but it is on my property and i want it gone.
Any advice would be greatly appreciated.

Sulli