Discovery service - Shocking

My son had a dental procedure in hospital. I firstly struggled to receive a quotation for the procedure until i emailed a complaint to the Service head. The procedure happened and on the 20th January i phoned them to inform them that we will utilize our gap cover to pay for the short fall. Discovery did exactly the opposite with one of the accounts. I have been struggling since then to rectify this matter. I contact them on most days, all i receive are reference numbers and a reminder of the 2 to 3 working day processing time. I spoke to different consultants each time and have to explain each time. Each consultant has some different response and yet again more reference number. Consultants promising to phone me with feedback which are not done. Doctors are now wanting payments and the gap cover is going to take another 2 weeks delay. I again sent an emails to the Head of Service and still no acknowledgment or response. I had a look at the Discovery website - I have not seen an email address or contact number where you can lodge a complaint. How funny is that. They might be inundated with all the complaints. Reference numbers and different consultants each time is not the answer