Lousy service from admin

I visited the emergency room end October to see a GP. Paid before leaving but was not given an invoice, only a receipt for payment. Later phoned to get the invoice as medical aid needs it for claim. Hospital doesn't have anything, need to contact ER accounts. Phoned them, voicemail only. Hospital says ER accounts phone lines are down. I left a message with my details and query, no response after 2 days. Called hospital again, ER accounts already closed for the day. Complained as they are not getting back to me, get told it's not their department, they can't help me. Medi-Clinic, I'm paying you as a company (and you are not cheap) and your staff should take ownership and at least try to help even if not their department. Please sort out your lack of service internally.