No response to previous requests to close credit card account

I have sent an initial email to ABSA on the 12th of April 2019 requesting assistance in closing my ABSA credit card account, as I have no use for it and don't feel like wasting money on account fees every month. I did receive acknowledgement of receipt of my request, but after several days of no further response, I followed up with another email, to which I received a reply that the relevant department will be in contact within a few working days. This was 3 weeks ago. Since then I have sent numerous additional emails, with no response. I have also sent an instant message on their Facebook page (25 April 2019) which to date (07 May 2019) has not even been read yet! Is it really so impossible to get a response?