want to make money and not care abouut the client

I went to Tigerberg hospital Dental department and wanted to extract a tooth and had to have a blood count test done. That was in April 2018 and they have never sent me an invoice or call me or email me to ask or tell me what the payment was. and they decided to hand me over to MBD credit company and then further more I made arrangement for payment and paid as i was suppose to. Then they couldn't find my payments and then NHLS handed me over again to another Credit company and now they want to charge me ridiculous amount of R4454 for a simple blood test that I had and now in September I did the same blood test and the company said I need to pay R32 for it and I paid it on the spot no problems. But yet the nhls wants to get R4454 out of me and never issued my very first invoice in 2018 I am still waiting for the first invoice.