Lego complaint: Billing and shipping

Lego shipped an item to me but never charged my card. A year later, I get my order put on hold. When I call, they tell me they never billed me, but shipped the item to me. The customer service agent then started saying how I have their unpaid product in my home and need to pay up for it. I explained that it wasn’t my fault that they shipped me something they never billed. It was their business mistake. He continued to tell that I need to make up for that mistake immediately. That no one has control over how these mistakes are made. He said because the item was back ordered, the time Lego had to bill me probably ran out, so now I was basically stealing from Lego by keeping unpaid merchandise in my home. I shouldn’t be paying for Lego’s mistake a year later or made to feel like a criminal because they shipped me something they never charged me for. In good faith, I gave them my payment. It’s not my fault they never billed it.