Not responding to emails

I received a letter from Life Health Care that an outstanding amount of R398.76 ref *** not paid by the medical aid. Letter signed by Thabo Nkoala. I’ve phoned the number on the letter ***, but there is no answer. I’ve also sent emails to *** 0n 20 June 2019 and 1 July 2019 requesting the medical aid statement proof of non payment and the hospital account. I’m still waiting for a response to my emails. My wife passed away on 1 April 2019 and the death certificate and ID was also attached to my emails