LG Won't Install Air Conditioner Due to Missing Invoice

We bought a new LG air conditioner, brand new, model year 2024. LG is asking for the invoice for installation, but we lost it during the move. They don't seem to understand this. Other companies don't ask for an invoice for air conditioner installation, so I don't get what the issue is. LG, however, insists on having an invoice, even though it's already visible in their system. I'm reaching out to the LG representative here: what you're doing is simply making things difficult for customers, not doing business. LG is nothing but regret.