Terrible service trying to get an invoice

The people here just couldn't care any less about getting back to you.

You make a simple request to get an updated invoice for your physio visits and they send you an invoice with the incorrect dates of the visits. So I request an updated one with the correct dates and they ask for the same document I've sent to them twice before hand already. Then when I follow up (every day) on the matter I get told the same thing over and over "we will take your details and call you back" or "we will escalate the matter" yet everyday I've called them after not being gotten back to and still nothing to this day.