Covid-19 Patient Intentional Harassment by Health Service Provider

Lancet partners(collectors and attorneys) harassing me because Lancet states that their claims are rejected by medical aid(my medical insurance) while medical aid proves they did not receive any claims from Lancet.

There are two invoices, and there is one that should be paid by myself and the other that should be paid by medical insurance however, but Lancet proceeds with ignorance and harassment forcing me pay for both.

Options to escalate and be assisted by supervisor after poor query handling by ground line agents where required and that too exhausted without resolution.