Blue Hills Cash Converters Sold My Laptop

I pawned my laptop in Blue Hills Shopping Centre branch. When I tried to get it back, they had already sold it. This was before my expiry date! They then told me there is nothing they can do about it, also every agent tell me a different story every time I reach out to find out what happened. This is *****. Why have contracts if they just going to breach them. THIS IS VERY UNPROFESSIONAL!!