I'd be tempted to ignore it. But if you want to talk to them you'll need to talk to their finance department, the details /should/ be on the invoice. If not, w

I'd be tempted to ignore it. But if you want to talk to them you'll need to talk to their finance department, the details /should/ be on the invoice. If not, wait until the red reminders - they will have contact details for the accounts dept on them Customer support which is likely outsourced, as many companies outsource their call centre and warranty fulfilment will have exactly zero tools to cancel invoices.