No payment on my account

I phoned discovery about 7 times about the same account that they didn't pay, every time when I phone it is a different excuse. I spoke to Deidre Nukar and she said it is not about the auth number but about the ICD10 code. The PMB ICD10 is on the invoice. She also listen to the telephone conversation about to get a auth number at discovery. Still no payment. I also spoke to Tamsin and she said she will phone me back about answers why it is not paid and no phone call from her. I phoned again and I got a answer I must full in a form so that they maybe can pay it. I then spoke to Shanna she is the client supervisor. She said she is putting the invoice in again for payment and that she will phone me on the 15th of August and tell me if they going to pay it. Still today the 20th of August no phone call. I phoned again and spoke to an agent and asked to speak to her and he said I can't he will send an email to get to contact me. This phone call was on 17th of August and still no call. I am a pensioner what is only getting sassa and I had to keep on calling discovery and every time the phone call is taking me about 25min or more. I phoned out R200 out on this account. I am very unhappy with the the service of discovery.