Strangely, I'm trying to get hold of them so they ...

Strangely, I'm trying to get hold of them so they can issue me an invoice and I can PAY what I owe - they haven't sent me an invoice for a month's rent. Their accounts department doesn't answer their email address or phones (20 minutes in "queue position one" with no answer one day, 15 in "queue position two" with no change another), and the staff on the main number is apparently incapable of transferring callers to the accounts team - they just give you the number they don't answer. Fantastic service! I'm sure they'll be VERY quick to contact me when it's overdue... perhaps I'll not answer the phone or their emails for a bit?