Unable to get a correct tax certificate from Bonitas Medical Fund

I received a Tax certificate on the 27th of June 2019. The tax certificate was incorrect. I raised the first query on the 28th of June 2019 and after several queries they acknowledge on the 10th of July 2019 that the certificate is incorrect and that they will escalate it to their IT people for corrections. Subsequent to that I have queried them a few times on progress and closure but get absolutely no assistance from the call agents apart from that they said it is still in progress. I have no means of further escalation and neither do I have a expected closure date hence my reason for this review as I have run out of options