Cemair lying about international lounge access they sell

I booked three tickets online and chose the add-on International Lounge access at OR Tambo. When we arrived at the international Bidvest Lounge at OR Tambo, I was told that they do not accept Cemair customers and that they don't even have an agreement with Cemair. Embarrassed in front of my colleauges, I phoned Cemair to enquire. They acted surprised and tried to make it the fault of Bidvest Lounge. I insisted that get me access to the lounge even if the CEO need to come and swipe his own card. I was asked for my number and told they will phone back. Quite some time later I received a Whatsapp message from someone by the name of Martin. He apologised and told me I can go in to the lounge. I told him we went to our boarding gates already because they took too long. He then asked me to email him a bank account confirmation letter so that I can be refunded. That was 24 May. I did that immediately and was ignored ever since. I keep on following up on this Whatsapp message, but with no response. I warned him that I'm going to write a hellopeter review and even that went unanswered.