NetCare No Responce to queries

Netcare Created a good app with flaws, in the app there is an online consultation which seemed like a good idea to use, i used it, spoke to the dr, Paid, but the issue begin when i started needing the invoice to claim the money back from my medical aid, i wrote couple emails to them and all i am getting is we have escalate the issue to the Relevant department, then silent they go. How can they develop an app that you can get an invoice that still confuses me other than that, the services are great