Accusations than explanation and solution to a problem

I was a member of the discovery medical aid scheme from 01 July 2020 and I terminated my membership with them on 30 September 2020. 15 months later (December 2021) I received an e-mail stating that I owe them money with no explanation of what was the money for, as of 16 February 2022 I received a further e-mail stating that apparently, a claim was initially approved and got rejected during their investigation. Last week I called discovery and spoke to 3 people(Bulelwa, Aphiwe, and Clearance). Clearance, I was not happy with the way she handled my query, it was more of accusations than providing solutions to my problem. I have requested for a call record where I did not disclose that I was pregnant when I took the medical aid and proof that they tried to contact me during the investigation. The call got cut off I don't know where it was an intentional or technical glitch however she did not call me back to date. I was looking for answers than accusations.